At least four people are dead and 10 others are injured after a bridge collapsed near Florida International University in Miami, officials say.
Rescue teams were still searching the rubble on Thursday night for victims trapped beneath the buckled footbridge.
The structure toppled over an eight-lane motorway on Thursday afternoon, crushing at least eight vehicles, according to police.
It is still unclear how many people were under the bridge at the time.
Miami-Dade Fire Chief Dave Downey said on Thursday night he could confirm at least four people were killed.
“This is going to be a long incident. We are going to have rescuers here through the night, if not longer,” Chief Downey said.
At least 10 people were treated for injuries at theKendall Regional Medical Center, including two who were in “extremely critical condition”, according to Dr Mark McKenney, director of general surgery.
The 950-ton (862-tonne), 174-foot (53m) bridge was erected on Saturday in just six hours over the highway, according to a story posted on the college website.
Witnesses told local media vehicles were stopped at a traffic light when the structure collapsed at around 1330 local time (1730 GMT).
“We’re working our way into the pile trying to create holes that we can actually physically see,” Miami-Dade Fire Department Division Chief Paul Estopian told reporters.
“As soon as I looked outside, I saw dust flying everywhere,” Tiona Page said. “I knew the bridge had collapsed.”