Crash scene investigators work to clear the scene of a collision at Dallas Parkway and U.S. Highway 380 in Prosper on April 22, 2014.
A major crash has slowed traffic near U.S. Highway 380 at Dallas Parkway Tuesday morning.
The vehicles involved in the collision, a van and a sedan, are out of the roadway, but one lane is blocked for emergency vehicles.
One of the vehicles, the sedan, had the roof removed by rescuers. One of the occupants was transported in critical condition by air ambulance to the Medical Center of Plano.
The condition of the other driver is not yet known.
The crash took place on the Frisco-Prosper city line.
The cause of the crash is under investigation.