VIDEO: Helicopter Lands on Roadway to Rescue Maryland Trooper from Crash

The Capital Beltway was partially closed in Maryland Thursday evening after a crash that involved at least three cars and left a Maryland State Police trooper with critical injuries, reports NBC Washington.

The trooper was parked on the shoulder of the Beltway during the investigation of a car crash when a second crash occurred nearby, state police said the initial investigation showed. A car involved in the second crash slammed into the trooper's car, trapping him inside.

A Maryland State Police helicopter landed on the Beltway and rushed the injured trooper to the University of Maryland Shock Trauma Center, state police said. He had critical injuries, officials said.

The crash involving a trooper stationed at the College Park Barracks occurred about 2 p.m. on the Outer Loop of I-495 north of Annapolis Road (Route 450), in the Lanham area, police said. Video footage shot from Chopper4 shows three cars with significant damage.