13 people injured in 'serious' multi-vehicle crash on Maryland's Chesapeake Bay Bridge: Police

More than a dozen people were injured in a "serious" multi-vehicle crash that occurred on the U.S.-50 Bay Bridge in Maryland Saturday morning, authorities said.

The incident occurred around 8 a.m. ET on the westbound span of the bridge, which crosses the Chesapeake Bay.

Investigators believe 23 vehicles were involved in a "chain-reaction crash" on the westbound span, the Maryland Transportation Authority Police said.

Additionally, approximately 20 vehicles were involved in a series of "secondary crashes," police said.

Thirteen people were transported to local hospitals, including two with serious injuries, police said. None of the injuries are believed to be life-threatening.

The westbound span of the bridge was closed for several hours following the crash, as tow operators were working to clear vehicles. All lanes reopened by 2 p.m. ET, the Maryland Transportation Authority said.

Authorities advised people to continue to expect delays in both directions.

Maryland Transportation Authority Police officers are investigating the cause of the crashes.

The bridge's dual spans are four miles long, making them among the longest over-water structures in the world, according to the Maryland Transportation Authority.

Also known as the William Preston Lane Jr. Memorial Bridge, it connects the eastern shore of Maryland with the areas of Annapolis, Baltimore and Washington, D.C.