CANTON, N.Y. -- Three people killed in an Oswego County crash were employees of a north country ambulance company returning from a call in Syracuse, according to news outlets.

State police identified three dead St. Lawrence County residents as Corey E. Moore, 50, of Canton; Gregg P. Williams, 58, of De Kalb Junction; and Roderick C. Cota, 63, of Norwood.

R.B. Lawrence, owner of R.B. Lawrence Ambulance in Canton, told the Watertown Daily Times they were his employees.

"We are such a small company that they are all family," Lawrence told the newspaper. "They are just great people. I am not sure how we replace them or how we go on, but we are still in shock on this and still trying to figure out all that happened."

A fourth man killed in the crash was Moonjohn Kim, 52, of Ellicott City, Maryland, state police said.

Dr. Moonjohn Kim

He was an interventional radiologist at Samaritan Medical Hospital in Watertown, said Krista Kittle, a hospital spokeswoman. Kim had worked there for the past six years.

"Dr. Kim was a gifted physician who was adored and deeply respected by his colleagues, staff and patients," the hospital stated. "He leaves behind a legacy of tremendous medical skill, talent and true compassion that impacted the lives of so many patients"

Kim is survived by his wife, Clara, and their three young children.

Lawrence said his employees were an ambulance driver, a critical care technician, and a mechanic, according to WWNYTV.

Friends, coworkers and ambulance services around the state showing their grief and support on social media suggested Moore was one of the ambulance company's head mechanics, Williams was an EMT driver, and Cota was both a supervisor and the critical care EMT.

The driver and technician had transported a patient to a Syracuse hospital earlier in the day and were headed home when their vehicle broke down near Pulaski, Lawrence told the Daily Times. The mechanic drove down to pick them up.

Officials identified the people killed as three St. Lawrence County residents and a man from Maryland. All four worked for medical services.

Fewer than five miles into the journey back, a milk tanker in front of them heading north for Mannsville jackknifed, according to State Police. The driver, 38-year-old Charles T. Howard III of Watertown, told authorities he swerved to avoid "several" deer in the road and lost control of the tractor-trailer, said Jack Keller, a State Police spokesman.

Moore, Williams and Cota's vehicle struck the disabled tractor-trailer and went under it, coming to rest in a nearby ditch. All three were pronounced dead at the scene.

Kim's vehicle struck the same truck soon after, police said. His vehicle passed under it and traveled more than 150 feet before stopping in the median where he was also pronounced dead, according to State Police.

Lawrence said he was told the lights on the tractor-trailer had gone out when it crashed, making it hard to see in the dark. The crash happened just before midnight.

"It's just terribly devastating to us all," Lawrence told WWNYTV.

State police are still investigating the crash. Keller said it was a clear night, and the roads were dry at the time. Investigators shut down the highway for nearly eight hours overnight while they worked the scene.