A bridge collapsed in Pittsburgh on Friday morning, sending three people to local hospitals with non-life-threatening injuries, officials said.
Five cars and a Port Authority bus were on the bridge at the time of the collapse, around 6:39 a.m. local time, city officials said.
Port Authority bus driver Daryl Luciani told ABC Pittsburgh affiliate WTAE he was driving over the bridge when he could feel it collapsing.
"I could just feel it. The bus was bouncing and shaking," he said.
Ten people reported minor injuries, including the three who were hospitalized, Pittsburgh Fire Chief Darryl Jones said. First responders trying to help in the icy conditions were among the injured, he said.
Responders rappelled about 150 feet to reach the collapse site, Jones said. Crews also made human chains to conduct rescues.
Officials are now working to make sure there are no victims under the collapsed bridge, Jones said.
The cause of the collapse is under investigation.
Pennsylvania Lt. Gov. John Fetterman called the bridge "a vital infrastructure artery" for the city, adding, "It's surreal this morning to see it completely collapsed."
"Thank God that school buses were delayed due to weather, so there was less traffic than normal. Thank God there have been no casualties reported at this point. I wish all of those who were injured a safe and swift recovery," Fetterman said.
The bridge was built in 1970 and has a length of 447 feet and a deck area of roughly 28,000-square-feet, according to Pennsylvania's Department of Transportation (PennDOT).
A September 2021 inspection by PennDOT listed the overall condition of the bridge as "poor," according to city documents.
The collapse occurred on the same day President Joe Biden was traveling to Pittsburgh to tout his bipartisan infrastructure law, which would provide $1.63 billion for bridges in the state. The program would provide $27 billion for bridges nationwide.
Biden visited the collapse site Friday afternoon, where officers told him a jogger passing by helped rescue people from cars.
As Biden surveyed the damage, he told local officials, "I've been coming to Pittsburgh a long time -- and as a former Pennsylvanian -- but I didn't realize there are literally more bridges in Pittsburgh than any other city in the world."
Biden vowed, "We're going to -- you're going to -- fix them all. Not a joke."
Pennsylvania has 3,353 bridges in poor condition, the second most after Iowa, according to federal data.
The Biden administration has repeatedly said it's up to local officials to determine which bridges receive federal funding.
"This collapse is just the latest in a long line of preventable, man-made disasters that prove what so many of us in Pennsylvania and around the country have been saying for years: Our infrastructure is failing our people," Fetterman said in a statement.
"We need to make use of the legislation President Biden ushered in, rebuild our roads and bridges, and fix our faulty infrastructure," he added.
The National Transportation Safety Board was on scene Friday night to start investigating the cause of the collapse. A crash reconstructionist will use a drone to map the scene before they begin removing debris, officials said.
"It's kind of like peeling the layers of an onion to see where things were, where they ended up in the collapse," Dennis Collins, senior accident investigator for the NTSB, told reporters. "Of course we're looking for indications of where it began."
ABC News' Sarah Kolinovsky, Victoria Arancio, Justin Gomez and Joshua Hoyos contributed to this report.