I-35W Bridge
Collapse
Dan Dorgan
Presentation to SCOH Annual
Meeting
I-35W Bridge History
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Construction started in 1964
Opened to traffic in 1967
Steel truss deck, 113 feet, 4 inches wide
64 feet high, 1,907 feet long, 14 spans
Four lanes of traffic in each direction
Carried 140,000 vehicles daily, including 5,700
commercial vehicles
• $440,740 to construct the piers
• $4,823,262 to construct the bridge
• Scheduled for reconstruction in 2020-25
I-35W Bridge - Looking North July, 1967
Bridge Rating
• Inspected annually since 1993; before that, was inspected every two
years
• Superstructure rated “structurally deficient” in 1990
• This was due to:
– Corrosion where the paint had deteriorated
– Poor weld details in the steel truss members and floor beams
– Bearings that were not moving as they were designed to move
– Existing fatigue crack repairs to the approach span beams
Maintenance Work at Time of Collapse
• Replace concrete overlay,
repair joints and lighting,
and install guardrail
• Work completed on outside
two lanes each direction
• Scheduled completion date
- September 30, 2007
• Cost - $9 million
• Contractor employees and Mn/DOT inspectors on bridge at collapse
The Collapse
• Occurs at 6:05 p.m.
Wednesday,
August 1, 2007
– Over 100 vehicles were on
the bridge at time of collapse
– 13 fatalities
– 105 injuries
Corps of Engineers video
The Response
The First 24 Hours
Mn/DOT’s Immediate Response
• 6:05 p.m. - Numerous concurrent
calls to State Patrol Dispatch (911)
and from field employees to RTMC
and Maintenance Dispatch
• 6:10 p.m. - District Emergency
Operations Center activated and
DEOC staff report to RTMC
• Immediate traffic control for ramp
and freeway closures provided by
FIRST units, maintenance units,
and contractors in the vicinity
Mn/DOT’s Regional Transportation
Management Center (RTMC)
Statewide Incident Response
• 6:20 p.m. – State Emergency Operations
Center and Joint Information Center
activated.
• Unified command center set up on
collapse site. Authority in command
changed as incident progressed:
– Mpls. Fire Department in charge of rescue
– Hennepin County Sheriff in charge of recovery
(Mn/DOT assisted with some demolition)
– Mn/DOT assumed command after recovery
was completed
Emergency Service Response
Mn/DOT Metro district
provides maintenance staff and
equipment
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•Mn/DOT structural engineers
called to site
• Effective response due to
communications, planning,
equipment, training, and
experience with incidents on
the Metro area freeway system
Traffic Response
• 6:20 p.m. - began converting temporary traffic control measures to
more long term traffic control standards.
• 20 changeable message signs activated
• Mn/DOT assisted state patrol and other enforcement personnel
• Instituted 24-hour staffed traffic control
• By 7 p.m. – Over 150 employees activated
• 11:00 p.m. - Detour maps for a.m. rush posted on Mn/DOT Web site
• Overnight – closed I-35W with temporary barricades and converted
Hwy 280 to a freeway.
Public and Media Response
• 6:10 to 8 p.m. continuous Mn/DOT
traffic radio coverage
• Detour maps and info provided on Web
and 511 Traveler Information
• Media briefings, interviews
• Coordinated responses with other
agencies/governor’s office
http://www.511mn.org
http://www.dot.state.mn.us/i35wbridge/index.html
Security Response
• Mn/DOT safety officers
statewide called in
• Homeland Security & FBI
investigate criminal or terrorism
potential
• OSHA ensures safety
• Navy divers assist recovery
• U.S. Secret Service for
president visit
• No-fly zone activated
Internal Agency Response
• Employees knew what to do, when to go, who to report to
• Aug. 2 – Lt. Gov. e-mail to employees
• Aug. 2 – State employee assistance available
• Aug. 6 – Lt. Gov./Deputy thank employees
• Aug. 8 – Tips to employees on handling threats
• Critical incident stress debriefings provided
The Response
Local and National
Governor’s Response
• Aug. 2 - Governor Tim
Pawlenty declares a state
of emergency and
activates State
Emergency Operations
Center
U.S. DOT Response
• Aug. 2 – U.S. DOT Secretary tours site and announces
$5 million grant to help pay for early expenses
Executive Branch Response
• Aug. 3 - First Lady Laura
Bush visits the site, victims
families
• Aug. 4 - President Bush
pledges to cut red tape that
could delay recovery
• Aug. 21 - President declares
emergency under Robert T.
Stafford Act authorizing funds
for safety and recovery
efforts
President Bush participates in a
briefing with Minneapolis Mayor R.T.
Rybak and Gov. Tim Pawlenty
Congressional Response
• Congress authorizes $250 million in Emergency
Relief money to repair and restore highway facilities
to pre-disaster conditions
Mn/DOT’s Continuing Response
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Investigation
Inspections
Traffic Recovery
Bridge Demolition
Bridge Replacement
Media/Public
Responses
Continuing Response
Investigation
The Search for a Cause
• Cause may not be
known for 12-14
months
The Search for a Cause
• National Transportation
Safety Board leads
investigation
• Forensic engineering firm
assisting investigation
• Consultant to review
inspection procedures
Continuing Response
Inspection
Inspection
• Aug. 2 - Governor directs Mn/DOT to inspect all bridges on the trunk
highway system in priority order
• Aug. 6 – Mn/DOT completes inspection of five bridges with the same
arch deck truss design as I-35W bridge
• Inspection continues of state bridges, structurally deficient and
fracture critical bridges priority
• Aug. 10 – Mn/DOT requests that local agencies and private owners
accelerate inspections of their bridges
• Dec. 1 - Mn/DOT’s goal to complete all state bridges inspections
Inspection
• Approximately 13,600 > 20 ft. long bridges in
Minnesota - 3,800 TH, 9,800 local
• 197 fracture critical bridges in Minnesota – 72 TH
and 125 local
• 34 pin assembly bridges - 15 TH and 19 Local
• 1,111 structurally deficient bridges – 106 TH and
1,005 local
Continuing Response
Traffic Recovery
Traffic Restoration
• Work to convert Hwy 280 to a freeway including closing atgrade signalized intersections to cross traffic, upgrading
ramp termini signal systems and lengthening frontage road
• Add lane each direction on I-94 from Hwy 280 to I-35W by
overlaying and restriping shoulders
• Many temporary projects on other Metro alternate routes
Traffic Distribution After Collapse
Transit
• Metro Transit assigned 25 extra
buses, ridership jumps 25-50%
• Advised public to “buy bus
passes, stagger work hours,
carpool”
• Began studying additional
service enhancements
Park-and-Ride use jumps after
I-35W bridge collapse
Continuing Response
Bridge Demolition
Bridge Demolition and Removal
• Aug. 6 – demolition begins to aid
recovery, Carl Bolander & Sons
Co., awarded demolition contract
• Aug. 20 – recovery completed,
site turned over to Mn/DOT
• Sept. 6 - Navigation channel
opened to commercial traffic
Bridge Demolition and Removal
• As of Sept. 26:
– Steel removed from river
– Corps will sweep channel
– Restrictions still on
recreational river traffic
– Some demolition will
continue after Oct. 15
– NTSB on site through end
of year
Continuing Response
Bridge Rebuild
Bridge Rebuild
• 189’ wide
• 10 lanes of traffic, five in each direction
• Designed to handle Bus Rapid Transit (BRT) and/or a
managed lane (like I-394 MnPASS)
• Designed to be LRT ready
Bridge Rebuild – Design Build
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Aug. 4 – Design Build teams pre-qualified
Aug. 14 – public involvement process begins
Aug. 21 – layout submitted to Minneapolis
Aug. 23 - RFP delivered to five design-build teams
Aug. 23 – all but 3 environmental permits acquired
Sept. 19 – project bid letting
Oct. 15 - work scheduled to begin
Dec. 2008 – projected bridge completion date
Bridge Rebuild - Review Process
• Minneapolis Municipal Consent hearing Sept. 20
• Technical Review Committee reviewed proposed
design
• Visual Quality Advisory Committee met with DesignBuild teams
Bridge Rebuild-Stakeholder Involvement
• Six open houses
• Community group
Meetings
• Presentations/listening
sessions
• Meetings with local,
state, federal officials
• E-mail alerts/
notifications
• Web site, online
comment form
• Handouts at park-andride lots
Responding to What We Heard
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Build bridge to accommodate future LRT
Build a quality, attractive bridge we can be proud of
Mitigate construction impacts
Maintain key road and bike accesses
Require DBE involvement
Keep us involved!
Bridge Rebuild-Environmental Review
• Environmental reviews accelerated due to
cooperation among agencies
• Includes a thorough analysis of the full range of
potential environmental issues for all aspects of the
project
• Met NEPA requirements
Bridge Rebuild
Legislative/Congressional Hearings
• Aug. 15 – Hearings with Minnesota House and
Senate Transportation Committee
• Sept. 5 – Mn/DOT staff testified before the U.S.
House of Representatives Committee on
Transportation & Infrastructure
Bridge Rebuild - Economic Impacts
• Economic factors create urgency to rebuild quickly
• Daily costs to motorists of additional travel time and
distance estimated at $400,000
• Reduction in state’s average net economic output is
an additional $113,000 per day
Continuing Response
Media/Web info
Media and Public Response
• Media interest worldwide
• Media briefings, interviews
• Mn/DOT directed to be
transparent in info provided
• AG’s office required retention
of all incident-related data
• 50+ data practices requests
• Dedicated I-35W Web site
includes all documents
Conclusions
What Went Right?
Lessons Learned?
What Was Done Right
• Employees willing to work, just showed up, returned from vacations
• Excellent employee response due to experience and training
• Good coordination with other Governor’s office/other agencies
• Good work relationship between Mn/DOT and contractor employees
• Other agencies/states called and emailed offering help
• Material suppliers speeded up delivery
• Permits, other documents approved quickly
• No Mn/DOT employees injured during response and traffic recovery
What Worked Right
• In-place incident management infrastructure
• Redundancy in RTMC camera/communications
systems meant no network breakdowns
• Improved emergency radio communications
• Mn/DOT Web site reduced number of requests
Issues with Investigation
• Media, communications between national/local
agencies
• Sharing field office
• Who had jurisdiction
• Turning over portions of bridge to Mn/DOT
Lessons Learned
• Consultant onboard to facilitate table top incident review exercise
• Cell phone service was overloaded
• Confusion about DEOC and CO roles and responsibilities
• Improved system for media inquires and data practices requests
• Confusion regarding what investigation results are public information
• Use caution posting detailed contact info
• Mn/DOT employees can work out of the box, be flexible, work in
strange locations and do what needs to get done!
Looking Ahead
• Litigation is pending
• Competing companies filing complaints against
Mn/DOT bidding process
• Rebuild will keep the agency in response status for
up to two years
I-35W Bridge
Downtown
Minneapolis
University
of
Minnesota
http://maps.google.com/