Here are the latest developments:
Three people were killed and six were injured in the mishap on the Sahar elevated corridor in Andheri East.
A part of the bridge collapsed around 11.30 pm, trapping several workers.
The workers were rescued by police and fire brigade officials and shifted to two hospitals.
The 1.8-km Sahar corridor is being constructed to link the Western Express Highway to terminal 2 of the Mumbai international airport.
Police registered a case of death due to negligence and of grievous hurt against officials of L&T. A senior inspector said safety norms appeared to have been flouted.
L&T, which is building the bridge, denied negligence and said the accident occurred despite all safety measures being followed.
Deepak Morada, vice president (corporate communications), L&T, said: "The cause of the accident will be investigated. Our priority is to provide medication to the injured. We will follow due course for compensation of the victims." (L&T's full statement)
Debris at the accident site is being cleared out. There are no reports of traffic disruptions.
The contractor and two supervisors arrested will be produced in a local court.
Last year, a similar accident was reported from a Metro rail construction site in Mumbai. A slab from a bridge collapsed, killing one person.