A collision between a Nissan sedan and flatbed tow truck on Saddle Road killed a 31-year-old Hilo man this morning, Hawaii County police said.

The victim, Calsey B. Santos, was pronounced dead at Hilo Hospital at 8:07 a.m. Tuesday. The Hawaii County Fire Department said Santos suffered "massive head injuries in the crash near the 19-mile marker at about 5:24 a.m. Firefighters used the jaws of life to free Santos from the wreckage.

Police said Santos was driving a 1994 Nissan four-door sedan traveling towards Hilo when he crossed the center line and sideswiped a Kona-bound 2005 UD flatbed tow truck.

The driver of the tow truck, a 48-year-old Kailua-Kona man, and his passenger, a 58-year-old Hilo man, were not injured.

Traffic investigators opened a negligent homicide investigation and ordered an autopsy to determine the exact cause of Santos’ death.

Saddle Road was closed in both directions between the 19- and 20-mile markers for about three hours while firefighters worked to free Santos and clear the scene and police investigated the crash. The road reopened at 8:36 a.m.