Interstate 270 has reopened following a 20 vehicle pile up crash that closed a portion of the highway for nearly two hours on Monday morning.

The accident happened on March 19th at approximately 5:20 a.m. in Germantown, Maryland.

According to WTOP News, a tractor trailer hauling slate and gravel was travelling along southbound I-270 when, for unknown reasons, it overturned, spilling its load across the roadway and causing a pile up crash involving at least 18 vehicles.

14 vehicles had to be towed from the scene and four people were injured in the major accident, but their identities and conditions have not yet been released.

The southbound side of I-270 was shut down between Middlebrook Road and Montgomery Village Avenue for around 2 hours as crews used heavy equipment to push the spilled slate and gravel to the side of the roadway and right the overturned big rig.

The highway was completely reopened around 8:00 a.m. but officials warn there may be lingering delays into the afternoon.