MassDOT has launched emergency inspections inside the Prudential Tunnel after concrete came crashing down on unsuspecting motorists.

No injuries were reported but the accident set off a chain reaction that has snarled traffic in the city. Some damage to vehicles was reported.

Massachusetts State Police responded earlier this afternoon to I-90 West inside the tunnel, where the state Department of Transportation said a “section of non-structural concrete at an expansion joint below Huntington Avenue became dislodged … and fell into the left and middle travel lanes.”

Traffic is being diverted while crews remove the debris from the tunnel.

“Motorists should be prepared for increased congestion in the area and seek alternate routes,” MassDOT said in a statement just before 3:45 p.m.

Highway Administrator Jonathan Gulliver will brief the media on the incident at 4:45.

“Recent freeze/thaw cycles caused the concrete to become saturated, freeze, and then delaminate as temperatures rose today,” MassDOT said.

“MassDOT crews currently have a two-lane closure in place and are conducting emergency inspections across the width of the tunnel to identify and remove any additional loose material in the area,” the agency added. “Further inspections will take place tonight and over the coming days to ensure the continued safety of the tunnel.”

This is a developing story and here is the video MassDOT provided: