Tractor trailer crash closes lanes on Bay Bridge overnight

BALTIMORE -- A crash involving two tractor-trailers on the Chesapeake Bay Bridge prompted closures overnight, but all lanes reopened before 6 a.m., Maryland transportation officials said Wednesday morning. 

It remains unclear when the crash happened, but the Maryland Department of Transportation said the scene was active as early as 4:40 a.m. 

The crash happened on the eastbound span of the highly-trafficked bridge, closing all lanes for at least an hour. The westbound span was closed but quickly reopened.

The eastbound lanes reopened around 5:45 a.m. but left heavy traffic in its wake. 

No injuries have been reported, and the cause of the crash remains unclear. 

This is a developing story and will be updated.