A bridge in the US city of Pittsburgh has collapsed with four vehicles, including a bus, on it at the time.
No deaths have been reported. Officials said 10 people sustained minor injuries, three of whom were taken to hospital.
The snow-covered Fern Hollow Bridge gave way on Friday morning, sometime after 06:00 local time (11:00 GMT).
The collapse happened just hours before President Joe Biden was set to arrive in the city to talk infrastructure.
Fire Chief Darryl Jones said first responders used ropes longer than 100 feet and formed human chains to pull victims to safety.
A nearby resident told the KDKA-TV local news channel that the incident “sounded like a huge snow plow… pushing along the surface with no snow”.
Residents have been asked to avoid the area after public safety officials confirmed they had to shut off a leaking gas line that goes under the bridge. A strong smell of natural gas is being reported in the area.
It remains unclear what caused the structure to cave in. Pittsburgh Mayor Ed Gainey said it had been inspected as recently as September.
The White House has said it is in touch with state and local officials, and Mr Biden intends to continue his visit as planned.
He is set to speak in West Mifflin, about 10 miles (16km) outside of Pittsburgh, later on Friday about the benefits of the infrastructure spending bill he recently signed into law.
The legislation includes $110bn (£82bn) to repair and rebuild roads and bridges.
Federal transportation officials say about 45,000 US bridges – including more than 3,000 in Pennsylvania – are in poor condition and may be eligible for the funding.
“This bipartisan infrastructure law is critical,” said Mayor Gainey at a Friday morning news conference. “At the end of the day, it’s critical that we get this funding.”
The American Society of Civil Engineers, which regularly scores US infrastructure on an A to F report card, currently gives the country a C- grade.