Maryland State Police on Monday said they are still working to determine the cause of a Sunday crash that shut down Route 301 for six hours and sent 11 people to the hospital.

An initial investigation shows that the driver of a Mercury Marauder going north on Route 301 at Clymer Drive crossed the median into oncoming traffic and hit a pickup truck head on, according to authorities. The accident then caused four other cars to crash and left one car on fire.

Police say 23-year-old Seth M. Nesbitt of Waldorf was driving the Mercury Marauder.

Authorities were still interviewing witnesses as of Monday afternoon, police said.