"Something like you'd see on TV, on CNN, from a battlefield someplace," said Schultz, who described cars, a minivan and injured people all over the road.
The pileup actually involved two separate accidents that occurred almost simultaneously in dense fog, police said.
"You got to the peak of the mountain and it just turned to pea soup," said Sandy Trumpower, assistant chief at Mt. Aetna Volunteer Fire Co., who was in charge of getting the injured to the hospital.
Westbound traffic was shut down for about 90 minutes. Nine ambulances responded and took the injured to hospitals in Washington and Frederick counties, police said.
"We had so many patients it was overwhelming at first," Trumpower said. "I had a lot of help from some other officers from some other companies. They helped be my eyes and ears."
Police said 16 people were hurt, but Trumpower said 17 people were taken to the hospital.
Four people were classified as top-priority patients, two others needed urgent medical attention and 11 had less urgent injuries, she said.
Seven people were treated at Washington County Hospital. One person was in serious condition, four were admitted in fair condition and two had been treated and released, a hospital spokeswoman said.
Frederick Memorial Hospital treated seven other accident victims, said Nursing Supervisor Cheryl Estep. She would not reveal the conditions of those patients.
The two or three other people in the accident might have refused treatment at the hospital, Trumpower said.