Florida bridge collapse: Prayers offered as four dead in 'tragic' incident

US president Donald Trump offered prayers after a newly-installed pedestrian bridge in Florida collapsed on Thursday, killing four people and leaving several others critically injured.

The walkway over one of the busiest highways in southern Florida was installed on Saturday and was designed to give students at Florida International University (FIU) safe access to the city of Sweetwater, west of Miami.

ReutersThe bridge was built after an 18-year-old student was killed trying to cross the highway last August.

But the 950-ton footbridge collapsed late on Thursday, crushing several cars waiting at traffic lights below. Nine people were found beneath the wreckage and taken to hospital. A rescue operation is ongoing.

Florida senator and former presidential candidate Marco Rubio, who is adjunct professor at FIU, said: 'Ironically this [bridge] was designed for safety ... it was going to be a signature project and one of its kind in terms of its engineering design.'

He added: 'The public deserves to know and the families deserve to know and the people who lost their lives deserve to know what went wrong. These people doing the engineering studies will tell us what went wrong. It will prevent something like this from happening again because we learn from those things.'

ReutersFour people were killed and several others taken to hospital.

Florida's governor, Rick Scott, said: 'Everybody is working hard to make sure we rescue anyone who can be rescued.' He added an investigation would find out 'why this happened and what happened' and ensure that anyone found responsible would be held accountable.'

President Trump tweeted his condolences and offered prayers for the situation.

FIU president Mark Rosenberg addressed the media on Thursday and said: 'On behalf of the entire FIU community, I want to express our condolences to all those family members, sons and daughters, loved ones involved. This bridge was about collaboration, about hope, about opportunity and about determination. This bridge was about strength and opportunity about being good neighbors with the city of Sweetwater. It was about goodness, not sadness. Now we're feeling immense sadness ... and our hearts go out to all those affected. We're committed to assist in all efforts necessary and our hope this sadness can galvanize the entire community to stay the course -- the course of goodness and hope of opportunity.' 

A local church in Miami added its support: