A St. Marys woman was killed Tuesday when the sport-utility vehicle she was riding in collided head-on with a Cameron County Ambulance.

Amy L. Williams, 38, of St. Marys, was pronounced dead at 1:14 a.m. Tuesday at the scene by Elk County Coroner Michelle A. Muccio, Muccio reported.

According to St. Marys City Police, there were seven patients in the crash, four of whom were entrapped.

All patients were transported for treatment at Penn Highlands Elk.

Police reported the crash happened at 12:32 a.m. Tuesday on Route 120 near 1991 Bucktail Road. Police, along with the Crystal Fire Department and St. Marys Area Ambulance Service, were dispatched to the scene of a two-vehicle accident between a Toyota SUV occupied by three adults, two juveniles and a dog; and the Cameron County Ambulance, occupied by two adults.

Police determined the SUV was traveling west in the westbound lane, when it traveled into the eastbound lane and struck the ambulance, which was headed east.

Muccio was called to the scene and reported in a press release, “The cause of death for Mrs. Williams is blunt force trauma to the chest, and her death has been ruled an accident.”

Also on scene was a Clarion-based state police corporal, who performed accident reconstruction, and a supervisor from Pennsylvania Department of Transportation, who responded due to the road closure. The vehicles had to be towed from the scene, too.

The road was closed for five hours and 45 minutes, police said.

A joint investigation by the St. Marys police and Clarion-based state police is ongoing.

St. Marys police said several emergency responders provided support at the scene and the hospital. Additional assistance was provided by Emporium-based state police, Ridgway and Fox Township ambulance services, Ridgway Borough police, a St. Marys animal control officer and emergency room staff at Penn Highlands Elk.