NTSB releases preliminary report into FIU pedestrian bridge collapse

Retensioning was occurring on bridge at time of collapse, report states

MIAMI-DADE COUNTY, Fla. – The National Transportation Safety Board on Wednesday released its preliminary report regarding the March 15 collapse of a pedestrian bridge that was meant to connect Florida International University with the city of Sweetwater.

The 174-foot-long bridge collapsed at 1:47 p.m. March 15 on Southwest Eighth Street at 109th Avenue, falling about 18.5 feet.

According to the report, eight vehicles that were stopped below the bridge at the time were fully or partially crushed.

Seven of the vehicles had people inside.

File: NTSB preliminary report into FIU bridge collapse

Authorities said one bridge worker and five people inside vehicles were killed. Four bridge workers and four other people were injured.

According to the NTSB report, the bridge was expected to be completed by early 2019 and was built using an accelerated bridge construction method -- "a method intended to minimize disruption of traffic."

NTSB officials said "the walkway, diagonals, and canopy comprising the bridge, which had been built in a lot adjacent to SW 8th Street," was moved from the lot March 10, "using transporters, into position across the roadway and then lowered onto bridge piers on either side of the roadway."

Traffic on Eighth Street was detoured during the installation period and the roadway near the bridge was entirely closed when the structure was being moved, officials said.

After the structure was moved into position on March 10, construction workers "de-tensioned the bridge diagonal members" on the north and south ends of the bridge, the report stated.

According to the report, "a construction crew was positioned on the structure working on re-tensioning the number 11 diagonal member connecting the canopy and the deck at the north end of the bridge" at the time of the collapse.

NTSB officials said two of the three westbound lanes below the north end of the bridge were closed to traffic at the time of the crash because a crane was being used. 

Five eastbound lanes were open at the time and eastbound traffic was not being detoured.

The report states that "the NTSB is evaluating the bridge design, the construction process and the construction materials."

NTSB officials are also investigating cracks that were found in the south and north ends of the bridge.

More forensic examinations of several structural components of the bridge will be conducted in the next month, as well as "destructive testing of multiple core and steel samples," the report stated.

All aspects of the collapse remain under investigation. The NTSB has not yet determined probable cause for the collapse.

"The preliminary report identifies several areas of inquiry but nothing conclusive as of yet," Sweetwater Mayor Orlando Lopez said in a statement. "The city of Sweetwater has been and will continue to cooperate with the NTSB as they continue to conduct additional forensic examination of several structural components and destructive testing of multiple core and steel samples to determine the probable cause of the collapse."


About the Author:

Amanda Batchelor is the Digital Executive Producer for Local10.com.