Safety Recommendation H-08-019
Details
Synopsis: About 6:05 p.m. central daylight time on Wednesday, August 1, 2007, the eight-lane, 1,907-foot-long I-35W highway bridge over the Mississippi River in Minneapolis, Minnesota, experienced a catastrophic failure in the main span of the deck truss.1 As a result, 1,000 feet of the deck truss collapsed, with about 456 feet of the main span falling 108 feet into the 15-foot-deep river. A total of 111 vehicles were on the portion of the bridge that collapsed. Of these, 17 were recovered from the water. As a result of the bridge collapse, 13 people died, and 145 people were injured.
Recommendation: TO THE FEDERAL HIGHWAY ADMINISTRATION: Modify the approved bridge inspector training as follows: (1) update the National Highway Institute training courses to address inspection techniques and conditions specific to gusset plates, emphasizing issues associated with gusset plate distortion as well as the use of nondestructive evaluation at locations where visual inspections may be inadequate to assess and quantify such conditions as section loss due to corrosion; and, (2) at a minimum, include revisions to reference material, such as the Bridge Inspector’s Reference Manual, and address any newly developed gusset plate condition ratings in the American Association of State Highway and Transportation Officials commonly recognized (CoRe) structural elements.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Highway
Location: Minneapolis, MN, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: HWY07MH024
Accident Reports:
Report #: HAR-08-03
Accident Date: 8/1/2007
Issue Date: 11/21/2008
Date Closed: 1/10/2013
Addressee(s) and Addressee Status: FHWA (Closed - Acceptable Action)
Keyword(s): Training and Education

Safety Recommendation History
From: NTSB
To: FHWA
Date: 1/10/2013
Response: We note that the FHWA updated its bridge inspector training courses and reference materials to include inspection techniques and conditions specific to gusset plates. We appreciate the FHWA’s working with AASHTO to include the updates in the new Guide Manual for Element Inspection, which superseded the CoRe structural element designations. As these actions satisfy Safety Recommendation H-08-19, the recommendation is classified CLOSED—ACCEPTABLE ACTION. Thank you for your continued efforts to improve bridge safety.

From: FHWA
To: NTSB
Date: 9/11/2012
Response: -From Victor M. Mendez, Administrator: In response to recommendation H-08-19 the Federal Highway Administration has taken positive steps to complete the NTSB recommendations. 1. The National Highway Institute (NHI) bridge inspection courses have been updated to include the inspection of gusset plates, with emphasis on plate distortion and the use of nondestructive evaluation or testing as necessary to supplement visual inspection. Some examples of updated courses available from NHI are: a. Fracture Critical Inspection Techniques for Steel Bridges (September 2011) b. Bridge Inspection Refresher Training (November 2011) c. Safety Inspection of In-Service Bridges - 2 Volumes (July 2012) 2. An update to the Bridge Inspector Reference Manual is complete (February 2012), and includes a new 3D-page topic on gusset plates. Gusset plates are now a new National Bridge Element in the AASHTO Guide Manual for Element Inspection, which superseded the old CoRe element designations. A no-cost electronic copy of the updated manual may be ordered from the NHI Store using the following link: http://www.nhi.fhwa.dot.gov/training/NHIStoreSearchResults.aspx?get=&COURSE_NO=130055&KEYWORD=&TITLE= Given the above described actions, we respectfully request that recommendation H-08-19 be classified as "Closed - Acceptable Action."

From: NTSB
To: FHWA
Date: 8/10/2010
Response: The NTSB is pleased that the FHWA revised the bridge inspector training courses as requested, that AASHTO approved amendments to its Manual for Bridge Evaluation (MBE) and Guide to Commonly Recognized Structural Elements (CoRE), and that these amendments will be incorporated in upcoming revisions to the bridge inspector curriculum. We are also pleased that the currently planned FHWA and National Cooperative Highway Research Program study will further pursue an understanding of gusset plates and their modes of deterioration. Accordingly, pending completion of these efforts, Safety Recommendation H-08-19 is classified OPEN – ACCEPTABLE RESPONSE.

From: FHWA
To: NTSB
Date: 3/23/2009
Response: Letter Mail Controlled 4/6/2009 1:26:07 PM MC# 2090197: - From Jeffrey F. Paniati, Acting Deputy Administrator: Thank you for the National Transportation Safety Board's (NTSB) Accident Report NTSB/HAR-08/03 on the Collapse of I-35W Highway Bridge, Minneapolis, Minnesota, on August 1, 2007. The report is very comprehensive, clearly outlining the findings and probable cause of failure. The NTSB made three new safety recommendations, H-08-17 through H-08-19 to the Federal Highway Administration (FHWA). The FHWA appreciates the three safety recommendations for improving the quality of bridge design (H-08-17), using appropriate nondestructive evaluation technologies in inspection (H-08-18), and enhancing our training courses for bridge inspectors (H-08-19). As former Federal Highway Administrator Thomas J. Madison, Jr., noted in his letter to you on January 6,2009, we have been communicating with the American Association of State Highway and Transportation Officials (AASHTO) to address these recommendations. The FHWA has begun updating and revising the inspection training courses offered through the National Highway Institute and other reference documents, such as the Bridge Inspector 's Reference Manual, to emphasize inspection issues associated with gusset plates, including corrosion and distortion. Inspection course materials for the inspection and evaluation of gusset plates will be the first order of work in the course development. The work has started and is expected to be completed by August 2009. The FHWA will work closely with the AASHTO in developing new condition ratings for gusset plates in the AASHTO CoRe structural elements. In the meantime, AASHTO is amending the CoRe document to include gusset plates. The amended CoRe document will be a ballot item for voting and adoption in the July 2009 Annual Meeting of the AASHTO Subcommittee on Bridges and Structures to be held in New Orleans, Louisiana.

From: FHWA
To: NTSB
Date: 1/6/2009
Response: Letter Mail Controlled 1/30/2009 2:12:58 PM MC# 2090046: - From Thomas J. Madison, Jr., Administrator: Thank you very much for your November 2 1 letter outlining the most probable cause of the collapse of the I-35W Bridge on August 1,2007, in Minneapolis, Minnesota, as well as the coctributing factors. You also discussed three National Transportation Safety Board (NTSB) safety recommendations (H-08- 17 through - 19) to the Federal Highway Administration (FHWA). First, I would like to thank you and your team for performing such a thorough job in the investigation of the collapse and for sharing the interim findings and lessons learned through a series of NTSB advisories and news releases. Based on the interim findings, the FHWA has worked with the State transportation departments and other bridge owners to make sure our highway bridges are safe for the traveling public. The FHWA appreciates the three very fine safety recommendations to FHWA for improving the quality of bridge design (H-08- 17), using appropriate nondestructive evaluation technologies in inspection (H-08-1 8), and enhancing our training courses for bridge inspectors (H-08-19). We have initiated communication with our partners in the American Association of State Highway and Transportation Officials (AASHTO) to address the recommendations to FHWA and the six new NTSB safety recommendations to AASHTO. We are analyzing the final report and recommendations at this time, and will provide a formal response to NTSB with a work plan outlining action items and a schedule for accomplishing them. Thank you again for your letter, and congratulations to the NTSB for a very complete investigation with recommendations for improving the performance of the Nation's highway bridges. If you have any questions or need additional information, please contact Mr. Myint