The circumstances of the crash still were being investigated Saturday, Kerns said. An accident reconstructionist from the Berkeley County Sheriff's Department diagrammed the accident scene, she said.
The accident closed the two-lane stretch of W.Va. 9 at the top of a hill for three hours, she said.
Police were dispatched to the scene at 3:44 p.m., and a Jefferson County 911 dispatcher said the accident was reported around 3:30 p.m.
All three vehicles probably were totaled, with the GMC ending up upside down in the eastbound lane, Kerns said. Mercer and the driver of the Ford Explorer, John Janszen, had to be extracted from their vehicles, she said.
Janszen, 35, of Harpers Ferry, W.Va., was flown to Washington County Hospital, where his condition was being evaluated in the Emergency Department on Saturday night, police and hospital officials said.
A 12-year-old male passenger from the Explorer also was being evaluated at that hospital, a hospital spokeswoman said.
Angela Janszen, 31, of Harpers Ferry, and an 8-year-old female passenger were taken to Jefferson Memorial Hospital in Ranson, W.Va., Kerns said.
The driver of the Honda, Valerie Williamson, 45, of Ashburn, Va., also was taken to Jefferson Memorial, Kerns said.
The conditions of Williamson, Angela Janszen and the young girl were not known on Saturday night, a hospital spokeswoman said.
After the head-on collision, the Explorer hit a telephone pole, Kerns said.
The Honda, which had been eastbound behind the Explorer, ended up in its original eastbound lane, Kerns said.