A sheriff's office spokesman said he could not comment on any aspects of the investigation because officers still were collecting information at the scene at 11 p.m.
Hagerstown resident Mike Mongan said his son, 19-year-old Corey Mongan, was the driver of the Oldsmobile and was being treated at Washington County Hospital for injuries to his ribs, shoulder and hand.
"(Corey's injuries) are not life-threatening. I wouldn't be here if they were," he said.
Mongan said at least two of his son's friends were in the car, but could not name them or specify their injuries.
Sheriff's deputies also were investigating a report of an overturned car in the Boonsboro area during the 11 p.m. hour, according to a department spokesman. The spokesman said he had no information on that crash.
In Franklin County, Pa., the rain did not appear to cause many accidents, but it did force the closure of roads and left residents with flooded basements scrambling. The hardest hit area in the county appeared to be Quincy, according to Denny Clopper, a Franklin County 911 dispatcher.
Clopper said up to 25 roads were shut down throughout the county, many for several hours, because of high water levels. Among the roads closed for the longest period of time were Pine Hill Road in Quincy, U.S. 11 in Greencastle and part of Wayne Road at Mt. Airy Road, according to Clopper.
Dispatchers fielded more than a dozen calls from residents in Quincy, Washington Township and Waynesboro, reporting basement flooding of up to 2 feet in some cases.
"We had almost 100 calls during the 3-11 (p.m.) shift," Clopper said. "That's a busy shift for five people."
By 11 p.m. Monday, 1.66 inches of rain was reported for a 24-hour period in the greater Waynesboro area, according to weather observer Todd Toth. Toth said about two-thirds of an inch was recorded between 9:30 p.m. and 10:30 p.m. alone.
"We're getting hammered," Toth said. "I'm not sure when the last time we had this much was."
Emergency dispatch employees in Berkeley, Jefferson and Morgan counties in West Virginia said there were few calls for accidents, traffic delays or flooding, almost none of which were considered serious.
Heavy rain hit the Tri-State area after dusk Sunday leaving several areas soaked. The National Weather Service's State College (Pa.) office announced a flash flood watch for Sunday evening and a flood warning through Wednesday for Franklin County. The National Weather Service's Baltimore/Washington office declared a flood watch for Washington, Berkeley, Jefferson and Morgan counties for Sunday evening, as well.
The service said moderate to heavy rain caused flooding in several areas and that a late evening storm had the potential of dumping another 1 or 2 inches of rain overnight.
About .71 inch of rain was recorded in Hagerstown, according to a Web site managed by weather observer Greg Keefer. The total is nearly a quarter of the normal amount of rain for the month of September (3.07), according to site data.
Totals from 8 p.m. to 11 p.m. for areas of West Virginia recorded by local branches of the National Weather Service were not available on its Web site.
Activity after 8 p.m. was a sharp contrast to the 24 hours before. Dispatchers and police spokespeople from areas including Hagerstown, Frederick, Md., and Martinsburg and Berkeley Springs, W.Va., said Labor Day was quiet on all fronts. Many said they were surprised the holiday was so quiet.
"Basically, it's been smooth," Washington County 911 dispatcher Joey Chojnacki said Monday afternoon. "There have only been a few (accidents), and they were minor."