Brazilian expressway collapses over metro tunnel

Television images showed a lane of the Marginal Tiete expressway caving into a widening pit alongside the construction site of the tunnel under a nearby river. The Sao Paulo state metro operator said on its website that tunnels dug for the new subway project had been flooded.

No casualties have been reported and public safety officials said all 50 workers were able to exit the tunnel. Two were treated for contact with dirty water that gushed through the site.

The cause of the collapse is not yet clear and conflicting information has been given.

In a press conference, Sao Paulo Governor Joao Doria said a sewage collector owned by water utility company Sabesp was hit but in the same conference Andre De Angelo, Acciona's country director in Brazil, said there was no collision between the excavator and the sewage network. “We are looking for the causes now. It probably has to do with the rains, with erosion. The tunnelling machine was 3m away from this collector, so there was no collision,” he said.

State prosecutors have opened a civil investigation.

Acciona said in a statement it has taken all required contingency measures after the incident.

Line 6 was originally due for completion in 2012, but was delayed several times as funding dried up amid a deep recession in Brazil. It is now scheduled for completion in 2025.

The planned 15km line, one of the largest infrastructure projects under construction in Latin America, will connect the Brasilandia district of northern Sao Paulo to the city centre.

Acciona won the contract worth €2.3bn (US$2.59bn) after the previous consortium left the project.