MIAMI _ The death toll rose overnight in the catastrophic collapse of a 950-ton pedestrian bridge at Florida International University in Miami-Dade County, as a search for survivors became a mission to recover bodies, police said before dawn Friday.
At least six people are confirmed dead, Miami-Dade Police Detective Alvaro Zabaleta told reporters at the scene along a normally busy, eight-lane thoroughfare where the 174-foot-long bridge came down Thursday afternoon.
Five people died at the scene and another person died at the hospital, Zabaleta said.
At least one of the deceased was an FIU student, Sweetwater Mayor Orlando Lopez said during a second press conference Friday morning. Students had been on spring break and the campus was less busy than usual this week.
Authorities withheld victims' names. The death toll could rise, Zabaleta warned.
"There is the possibility, the sad possibility, that under the concrete there may be additional vehicles," Zabaleta said.
At least eight vehicles were beneath the broken concrete slabs, officials have said.
Miami-Dade Police Director Juan Perez said for the time being, they would not provide information about casualties.
"We're not going to talk numbers anymore," Perez said about updating tallies of the injured and the dead. "We expect to find other individuals down there. So what's probably best is we wait to find all the vehicles and we'll give you a grand total of the fatalities and the magnitude of this event."
The bridge was put in place Saturday and was to be completed in 2019. It crossed Southwest Eighth Street and was intended to be a safe passageway for students and connect the school's campus to the city of Sweetwater to the north.
State and federal investigators began Friday to figure out why the span failed.
"The people of South Florida have been through a lot, obviously, over the last several weeks, " National Transportation Safety Board chairman Robert Sumwalt III said Friday, referring to the Feb. 14 mass shooting at Marjory Stoneman Douglas High School in Parkland, when 17 were killed and 17 wounded. "And this is just yet one more tragedy to add to that sad book."
A "go team" of specialists, including experts in civil engineering and materials science from NTSB will study the failed project. He expects the team to work on the scene for five to seven days.
"Our entire purpose is to find out what happened so we can keep it from happening again," Sumwalt said.
Authorities declined to address reports about whether the bridge had undergone testing before the Thursday afternoon collapse.
"Those are answers we're looking for as well," said Perez. He added that the entire project, from contract to catastrophe, will be reviewed.
U.S. Sen. Marco Rubio had tweeted Thursday night, "The cables that suspend the #Miami bridge had loosened & the engineering firm ordered that they be tightened. They were being tightened when it collapsed today."
Miami-Dade County Deputy Mayor Maurice Kemp said, "We have not confirmed that there was a stress test. The key here is not to jump to conclusions, not to speak on speculations, but to work on fact. And that's what we plan to do."
Steps taken Friday will include moving in heavy equipment to break the largest, still solid piece of concrete and remove it so victims can be recovered, what Perez called a "tedious process. Our goal is to get everything removed so we can get to those victims."
Firefighters got the call for help at 1:30 p.m. Thursday. Search and rescue crews worked into the night to try to find survivors.
The $14.2 million bridge, which FIU said "swung into place" on Saturday, had not yet opened to the public.
