A tour bus overturned on the Baltimore-Washington Parkway early Sunday, sending one person to the hospital, according to U.S. Park Police.

The incident happened around 12:50 a.m. on the southbound lanes of BW Parkway at Maryland Route 198.

The bus was carrying about 40 passengers when it overturned, according to park police. One person was transported to a local hospital with life-threatening injuries.

The incident caused the southbound lanes to close through the early morning, later reopening shortly before 7:30 a.m., according to WTOP Traffic Reporter Steve Dresner. The northbound lanes remained open.

See a map of the location below: