Home » Education » I-35 W Bridge Collapse Tragedy and Response Report

I-35 W Bridge Collapse Tragedy and Response Report

by Suleman


The Interstate 35 W Mississippi River Bridge (I-35W) was completed in 1967 and with 14 spans, the bridge was 1,907 feet long and 140,000 automobiles travelled across the bridge on average in 2007, rendering it the second busiest highway in Minneapolis. The Federal Government claims control of the bridge, but the State of Minnesota controlled it and kept it.

The failure of any infrastructure will have a catastrophic effect on the country, and there was no exemption to the disintegration of Interstate 35 W (I-35W) Mississippi River Bridge when it eventually had a detrimental impact on the U.S. economy. Lives and belongings were also lost during this collapse when citizens lost their vehicles and lives to the collapse on that fateful day; several people also received injury.

            The I-35 W bridge was built in 1967 and its collapse has exposed the vulnerability of other infrastructures to destruction and it has aroused everybody’s consciousness about the neglect of some key structural designs as regards their pending failure, it has further made the respective authorities to closely monitor and regularly inspect these infrastructures in order to guard against their failure (Subramanian, 2008).

I-35 W Bridge Collapse Tragedy and Response Report

            It is imperative to look into the collapse of this bridge and investigate the causes of the bridge and check whether the disaster could have been averted by taking precautionary measures. The events that followed the collapse of the bridge would also be closely monitored vis-à-vis the response of the emergency management team in ensuring that the amount of casualties was reduced to a minimum.

            The findings gotten in this paper would help prevent future occurrence of infrastructural destruction and it would ultimately improve the response of the emergency unit in managing situations such as the one that befell the state of Minneapolis in 2007 as we seek to ensure adequate and effective disaster planning and management.

The ‘I-35W Bridge’ Tragedy

There have been warnings concerning the imminent collapse of the 1,900-ft long I-35 W Bridge in Minneapolis as several experts had cautioned the authorities on the likelihood of the disaster. The unfortunate incident occurred on the 1st of August, 2007, just a few minutes past six, the Interstate highway with eight lanes crumbled inside the Mississippi River, plunging people into the Mississippi River and separating them from their vehicles. People and vehicles were displaced around the north and south ends of the bridge. The I-35 W Bridge collapse became a national tragedy and there were doubts in some quarters that the accident was caused by terrorist attacks due to the magnitude of the collapse. The I-35 W Bridge, which carries about 140, 000 vehicles a day is the second busiest bridge in Minneapolis and what was the most occupied bridge turned into a disaster scene as the structures of the bridge practically collapsed in just a space of four seconds (I-35W Bridge fact sheet. Minnesota Public radio, 2007).

Tragedy was confirmed in Minneapolis, when a cloud of concrete dust surrounded the vehicles that plied the I-35 W Bridge on that black Wednesday as some parts of the concrete structure of the bridge plunged into the Mississippi River (Subramanian, 2008).

On that fateful evening, the I-35 W Bridge suddenly crumbled followed by the two contiguous spans. The two back spans of the collapsed bridge was suspended in the air for a second before each span fell in the river, the first span fell back into the north side of the river while the second span catapulted sideways into the south side of the river.  When the dust that beclouded the bridge cleared, it was only less than the length of the bridge that was still erect as the major length of the bridge had ultimately collapsed (Subramanian, 2008).

            The collapse had about 110 vehicles trapped in it, about 121 people were reported to have been injured, while about 13 lives were lost in the river and it was quite surprising that a bridge of such magnitude could fall like a pack of cards. During the time of the collapse, the bridge was carrying about 120 vehicles, with about 160 people on it (Petroski, 2007).

            The actual trigger of the breakup of the bridge could not really be established and the bridge had been closely monitored and inspected yearly since 1993 (Weeks, 2007). A analysis was performed on the bridge in March 2001 on the fatigue cracks in the main truss and floor truss structures (Interstate 35W Mississippi river bridge fact sheet, 2006). Although state reports from 2001 to 2005 showed that there were signs of failure in the bridge trusses, there were no signs of failure in the deck truss, and as researchers from the Department of Civil Engineering at the University of Minnesota stated that the deck truss system was not likely to fail, the replacement of the bridge was delayed (American Society of Civil engineers, 2007). There have already been alerts that in the event of an infrastructure collapse, the bridge had no alternative provision to cater for the weight of the cars. The collapse of the bridge in 2007, which occurred less than 15 years after the expected rebuilding date, when the bridge was placed up for reconstruction in 2020 to 2025.

As citizens were definitely not prepared for a disaster of such proportions, the Minnesota Department of Transportation came as a surprise (Article showing comprehensive bridge rating details, 2008).

            There were indications of the I-35 W tragedy, when the National Bridge Inventory database of the United States Department of Transportation rated the bridge as being structurally deficient and that the bridge needed to be replaced or reconstructed urgently(Mcnichol, 2007).

Another report in 2006 discovered that five main truss members were likely to fail and should be modified with high performance strength bolts and steels as the report stated that the replacement would further strengthen other members of the bridge. A few weeks to the unfortunate collapse of the bridge, minor work was already started in repairing some sections of the congested highway. Four of the eight lane highway had already been closed for resurfacing at the time of the collapse (Subramanian, 2007).

            Several researches have linked the most likely cause of the collapse to: Rusty steel, worn out weld joint and the eroding effect of bird droppings and other chemical pollutants. The National Transport Safety Board (NTSB) finally stated that the gusset plates that connected the steel beams were merely half of what the thickness is meant to be and this played a great role in the collapse of the bridge (Subramanian, 2008).

Emergency Management Team’s Action

There must be an adequate disaster planning in the event of a disaster as the ability of the emergency management team to respond promptly to disaster issues playa great role in reducing the effects of the disaster. The response of the Department of Homeland security and emergency management team (HSEM) was marvelous in the collapse of the I-35 W Bridge and worthy of commendation, while about 50 agencies were there for the rescue and recovery operations (DHS, 2007). The Minneapolis were the first to arrive at the scene of the tragedy as it took them just three minutes to get to the tragedy scene, while the Minneapolis Fire Department arrived the scene in just about thirty seconds after the police arrived (Uddin et al, 2008).

            At the time of the tragedy, it became necessary to urgently rescue the people that were trapped in the water and the vehicles on the bridge. The HSEM team promptly responded by carrying out the injured people to the area hospitals, people were taken to the hospitals depending on the seriousness of the injury they sustained. They ranked the importance of the injured people by promptly responding to them in a triage method.

            Some vehicles were ignited by fire and the fire fighting units responded by sprinkling water on the vehicles to save people from the fire and stop the fire from damaging the vehicles further. A distress call was immediately sent to the emergency management units, law enforcements and officials from the fire service of the local and states authorities.

            The Homeland Security and Emergency Management (HSEM) going by their wealth of experience knew the steps to take as they responded to the emergency situation and carried out the recovery operations in a professional manner. The success of the emergency operations could be traced to the fact that the team that worked together in the recovery and rescue operation had previously worked together before as a unit. The fast response of the emergency team to the site of the tragedy shows their effectiveness and depth in disaster planning and management.

            The grant program of the Federal homeland security recognizes Minneapolis as a Twin City Urban Area (TCUA). Grants have been given to the TCUA by the Department of Homeland Security (DHS) and these has benefited the state of Minneapolis as it has helped them in coping with the adverse effect of the tragedy (DHS, 2007).

            Immediately after the collapse, the Minneapolis Fire Department (MFID) dispatched fire fighting experts to the scene of the incident at exactly 6:06 pm and it took about five minutes for them to arrive at the tragedy scene as the MFID arrived at exactly 6:11pm and they began assessment of the scene and subsequently began rescue and recovery operations (Subramanian, 2008).

            The fire fighting team tried to quench the fire that ravaged the south side of the bridge, while the medical unit of the emergency management team immediately gave a cardiac arrest victim cardiopulmonary resuscitation (CPR) (U.S. Fire Administration/Technical Report Series, 2007).

            The emergency management team was also helped by commuters, passers-by and the survivors of the tragedy in their rescue operation. The emergency management team successfully rescued some people from the water, while trapped people were pulled out from their vehicles. The emergency team faced a serious problem when the onlookers were too much to bear. At around 6:45 pm, the police played a great role in dealing with the problem of the mob of onlookers as they shouted on them to leave the damaged bridge and they cautioned them that stomping the bridge could collapse the already damaged bridge further and more lives stood the risk of getting entrapped in the bridge. About ten hospitals were in hand to receive the victims of the tragedy.

            It was pertinent for the responsible authorities to allay people’s fears as they thought the tragedy was an act of terrorism, the Department of Homeland Security promptly played this role by assuring the people that the tragedy was not an act of terrorism, but a collapse of the bridge due to the failure of some members of the I-35 W bridge (Mcnichol, 2007).

Was Mitigation Neglected?

Considering the fact that there had been impending warnings of the failure, it is pertinent to affirm whether mitigation was neglected and whether the responsible authority did not take the step they were required to take in averting the tragedy.

            But, due to the fact that the causes of the I-35 W tragedy were numerous, it is difficult to blame anybody for the tragedy as it all seemed that the tragedy was inevitable as it is known that structures are prone to failure and this actually depended on their usage, the support structures were already overstressed, while the support beam were gradually losing balance and decaying. The fact that the I-35 W Bridge was the second busiest highway in Minneapolis makes its collapse an unavoidable occurrence, but it is the timing of the collapse that was surprising, considering the fact that the bridge was scheduled for reconstruction in 2020-2025 (Mcnichol, 2007)

            Prior to the unfortunate tragedy, the bridge was always giving signs of an imminent collapse and the efforts to save the bridge from collapse by means of reconstruction efforts on the bridge could have played a role in its failure as the reconstruction effort could have ultimately led to its collapse due to the weight of the heavy construction process taking place on the bridge.

            The fact that the emergency team promptly responded as they were in hand to rescue people and recover bodies means that they did all that was within their power to reduce the effects of the tragedy.

            People have blamed the collapse of the bridge to lack of proper maintenance and they claim that if the bridge had been adequately maintained, it would have lived up to the time it was scheduled for reconstruction.

            The fact that the I-35 W Bridge was expanded from four lanes to six and then to eight could have played a role in its failure as it now had to carry more weight that it was not originally designed for (Subramanian, 2008).  


            A bridge serves lots of purpose and its destruction could mean a lot to a country’s economy (Xanthakos, 1998). The collapse of the I-35 W Bridge has further aroused the consciousness of the United States Government to the non-reliability of structures. The fact that the bridge collapsed before its predicted date has made the relevant authorities that nothing is certain.

            The I-35 W Bridge tragedy is the most recent infrastructural destruction as it has further raised concerns over the safety of bridges in the United States. The collapse of the bridge should not be put aside as it is a major disaster that had far reaching consequences as it now made people to further doubt the road transportation system.

            The most potent reason for the collapse was traced to a flaw in the design and this has made the government to properly scrutinize designs of infrastructures as the United States can not afford to lose more people due to the deficiencies in some people’s design.

  • American Society of Civil engineers. (2007). History and Heritage of Civil Engineering. (2007). Retrieved on December 17, 2009, from http://live.asce.org/hh/index.mxml?lid=158
  • Article showing detailed Information regarding the bridge’s rating. (2007, August 03). Retrieved on December 17, 2009, from http://www.msnbc.msn.com/id/20102713/
  • DHS. (September, 2007). DHS action plan and rescue measures. Retrieved on December 17, 2009,   from http://www.dhs.gov/xprepresp/
  • I-35W Bridge fact sheet. Minnesota Public radio. (2007, August 03). Retrieved on December 17, 2009, fromhttp://minnesota.publicradio.org/display/web/2007/08/03/bridge_background/? rsssource=1
  • Interstate 35W Mississippi river bridge fact sheet (2006). Fatigue evaluation and redundancy  analysis (Draft report).  Minnesota Department of Transportation.
  • Mcnichol, D.  (2007, November). Rebuilding a Bridge.  Roads & Bridges, 44- 54.
  • Petroski, H. (2007).  Learning from bridge failure: Collapses such as the I-35W in Minneapolis give engineers the best clues about what not to do, LA Times,op-ed.
  • Subramanian N. (2008, February). I-35W Mississippi river bridge failure– Is it a wakeup call? The Indian Concrete Journal, 29-38.
  • U.S. Fire Administration/Technical Report Series (2007, August).  I-35W Bridge Collapse and  Response. Department of Homeland Security United States Fire Administration National Fire Programs Division.
  • Uddin, S.G., Barnett D.J., Parker, C.L., Links, J.M & Alexander, M. (2008).  Emergency Preparedness:  Addressing a Residency Training Gap.  Academic Medicine, 83(3), 298-304.
  • Weeks III, J. A. (2007, August 06). I-35W Bridge Collapse Myths and Conspiracies. Retrieved on December 17, 2009, from http://www.johnweeks.com/i35w/i35wmyths.html
  • Xanthakos, P.P. (1998). Bridge Substructure and Foundation Design. New York: Simon & Schuster.

You may also like

Leave a Comment