A Monroe man suffered potentially life-threatening injuries after being involved in a three-vehicle crash on South Middlebush Road on Feb. 16.

South Middlebush Road was closed for about four hours during the investigation.

The man, Robert Held, 76, was transported to an area hospital after the crash, in which his Nissan Altima crossed over from the northbound to the southbound lane. The car first sideswiped an ambulance, then crashed head-on into a car driven by Terrence Brown, 50, of Franklin Park.

The ambulance, driven by Matthew Hall, 24, of Bloomsbury, continued a short distance before leaving the road, according to a press release from Franklin Township Police.

Brown was transported to an area hospital with non life-threatening injuries, and Hall and his 28-year-old passenger were not injured, according to police.

Members of the Franklin Township Police Department’s Traffic Safety Bureau and the Somerset County Prosecutor’s Office Collision Analysis Reconstruction Team were on scene conducting the investigation, according to the release.

Anyone with information about the incident is asked to contact Ptl. Jose Jaime of the Franklin Township Police Department’s Traffic Safety Bureau at (732) 873-5533 extension 3143.