Two people were killed and more than two dozen were hurt, with injuries ranging from cuts to broken bones, officials said. At least one person was critically injured.
"All hell broke loose," said Joe Colony, who has been coming to Cherrystone Family Camping & RV Resort campground along the Chesapeake Bay for 30 years. "We got an emergency message on a cellphone and within 30 seconds, the thing hit and it blew down 40, 50 trees in the park."
The National Weather Service had issued a tornado warning for the area about 9 a.m. EDT on Thursday. A team was dispatched to determine if a twister had hit.
About 1,300 people were at the campground, readying for a summer day of swimming pools, mini-golf, pier fishing and other activities at the 300-acre resort in rural Northampton County.
Joe Micucci said he and his wife couldn't escape in their car because hail was the size of softballs. The couple rode out the storm in their camper.
"We saw at least five (campers) that were flipped over. One was completely gone and only had its wheels left," said Micucci, of Washington Township, New Jersey.
Across the country in Spokane, Washington, severe thunderstorms knocked out power to more than 60,000 customers and damaged dozens of homes Wednesday. One driver suffered life-threatening injuries when a tree slammed onto his car, impaling him. Severe thunderstorms were forecast for the northern Plains on Thursday and could threaten the Deep South and mid-Atlantic.
In Virginia, State Police spokeswoman Corinne Geller confirmed the deaths.
Eastville volunteer firefighter Brittney Eder said she left the campground before the full force of the storm hit.
"It came in real quick," she said. "The sky turned jet black."
Micucci and others were evacuated from the campground to a nearby high school. He said he wasn't sure when he would be able to go back and survey the damage.
Peter Glagola, spokesman for Riverside Shore Memorial Hospital, said the hospital was treating more than two dozen patients as of Thursday afternoon, most of which were in fair condition with injuries ranging from cuts to broken bones.
Glagola said more patients were expected to be brought to the hospital, which is about 30 minutes north of the campground. One patient in critical condition was flown to VCU Medical Center in Richmond, he said.
Hospitals in Virginia Beach and Norfolk had been preparing for mass casualties but had received just three patients, one of which was taken to a nearby children's hospital, said Sentara Healthcare spokesman Dale Gauding
Coast Guard spokesman Petty Officer 3rd Class David Weydert said crews also were responding to reports of boats overturned in the water in the area. Good Samaritans pulled at least three people from the water, he said, though their conditions were unknown.