WALTERBORO --- A woman who died in a single-vehicle crash Tuesday on Interstate 95 had been en route to a memorial service for her husband who died earlier this month.

Lynell Searcy Stapleton, 76, of St. Simons Island, Ga., died at the scene of the 8 a.m. wreck near mile marker 55 in the Walterboro area, according to Colleton County Coroner Richard Carterd. He said Stapleton was driving northbound in a 2004 Chevrolet SUV when the vehicle hit a guard rail head-on, traveled down an embankment and overturned.

Carter said three passengers -- the driver's daughter and two grandchildren -- were slightly injured and were treated at a hospital.

The cause of the crash is unknown. The S.C. Highway Patrol is investigating. The patrol said the wreck blocked one lane of traffic for two and a half hours.

Stapleton was the wife of the late George J. Stapleton, a retired Army colonel who died at age 78 on Nov. 8 at St. Simons Island. She was headed to West Point for a memorial service for her late husband when the accident happened, Carter said.