Three people are in the hospital on Christmas Eve, including two Pennsylvania State Troopers.

Pennsylvania State Police say they are investigating a vehicle-pedestrian collision that happened shortly after midnight on Christmas Eve.

State Police say the collision occurred in Pittsburgh on Interstate 279 North near mile marker 3.

Police say a Ford Focus became disabled on the Interstate and the driver exited the vehicle to push it off the roadway. A passerby pulled off the roadway to assist when a black Dodge Ram 1500 struck the driver pushing his Ford Focus. Police say the Ram Truck left the scene.

Troopers arrived on the scene and while they were investigating, troopers said a Toyota 4Runner hit a marked police vehicle that had its emergency lights and arrow sticks activated.

The Troopers and the driver were all taken to local hospitals.

Police said they're now looking for the driver of the Black Dodge Ram 1500 that drove away. Anyone with information is asked to call Pennsylvania State Police Pittsburgh at 412-787-2000.