Media playback is unsupported on your device Media caption Miami rescue workers search for survivors

Rescue crews are now focusing on recovering victims buried beneath the collapsed bridge in Florida that left at least six people dead, police say.

The 174ft (53m) concrete bridge near Florida International University in Miami fell on to an eight-lane street on Thursday.

Police say more bodies could be found in crushed vehicles beneath the rubble.

Emergency crews searched for trapped victims overnight while at least nine people were taken to hospital.

Miami-Dade Fire Chief Dave Downey confirmed on Friday that authorities "determined that there's no longer any survivors", after visual and canine searches proved unsuccessful in finding anyone alive.

"We know there are bodies down there and we can't get to them. It's terrible," Miami-Dade Police Department director Juan Perez told a local radio station on Friday.

Authorities have switched from rescue to recovery mode and are focused on removing "all of the cars and all of the victims in a dignified manner", said Miami-Dade County Deputy Mayor Maurice Kemp.

Ms Kemp also insisted that a thorough investigation would be done to determine what led to the bridge collapse.

What is the latest on the victims?

Six people have been confirmed dead but rescuers are still uncovering cars in the rubble and expect to find more.

Officials at Florida International University confirmed a student was among those killed.

The victim's name was not released by authorities or the school, but local media have identified her as freshman Alexa Duraan.

Lynette Gomez, her sorority sister, told CBS Miami that Ms Duraan was driving her car when the bridge collapsed and is still missing.

Media playback is unsupported on your device Media caption Florida officials: We found eight trapped cars and multiple fatalities

Another person riding in the passenger seat was able to escape and is being treated for injuries at Kendall Regional hospital, CBS reports.

"He was able to get out but we haven't been able to find out where she is," her friend Manny Perez said.

The death toll could still rise as more cars are uncovered.

"We cannot confirm identities of who is in there, so we're caught in a bad place right now. The last thing we want to do is disclose names," Miami-Dade Police Director Juan Perez. "We're trying to navigate through some difficult times."

What do we know about the bridge?

The span connected the college to a student housing area and had long been requested by students at the university so they could avoid the traffic below, according to the Miami Herald newspaper.

In August 2017, a student was hit and killed by cars while crossing the busy road.

Munilla Construction company (MCM), a family-owned contractor that helped build the bridge, tweeted "thoughts and prayers" for those affected by the tragedy.

FIGG Engineering said it also was behind the bridge project. Both firms said they would co-operate with investigators.

The bridge was erected on Saturday in just six hours.

It was built using a method called "accelerated bridge construction" to avoid traffic disruption. A major section of the bridge was assembled on the side of the road and then raised into place.

The university had touted the new swinging span on Twitter just days ago.

Senator Marco Rubio said the bridge, which was still in the process of being installed, was having its cables tightened when it collapsed unexpectedly.

What have eyewitnesses said?

Witnesses told local media that vehicles were stopped at a traffic light when the structure collapsed at about 13:30 local time (17:30 GMT).

One witness told ABC News that the screams coming from the cars were "terrifying".

"As soon as I looked outside, I saw dust flying everywhere," Tiona Page said. "I knew the bridge had collapsed."

Media playback is unsupported on your device Media caption Miami bridge collapse witness: 'This is crazy'

Giovanni Hernandez told CNN affiliate WSVN it "sounded like a bomb, like multiple bombs in one".

"It sounded like the world was ending, and when you look back, all you see is the bridge on the floor. It was awful."