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.
The span, which connected the college to a student housing area in the city of Sweetwater, had long been requested by students and staff at the university so they could avoid the traffic below, according to the Miami Herald.
The 174ft cable-supported footbridge was to be publicly opened in 2019, local media say.
Costing $14.2m (£12.5m), it was funded by the US Department of Transportation..