(Reuters) - Rescuers on Wednesday found alive three people who had been lost in a West Virginia mine for four days after crawling in through a ventilation shaft, and brought them to the surface, a state spokeswoman said.

Erica Treadway, 31, Kayla Williams, 25, and Cody Beverly, 21, were all being taken to a hospital for treatment after the rescue, said Samantha Smith of the West Virginia Office of Miners’ Health, Safety and Training. Smith said she had no immediate information on the condition of the three, who had been stranded in the Rock House Powellton mine near the town of Clear Creek since Saturday.

A fourth person who was with the group when they entered the mine while riding all-terrain vehicles, 43-year-old Eddie Williams, found his way out on Monday to alert authorities about his missing friends.

Randy Williams, the father of Kayla Williams, one of those rescued, told an ABC News affiliate that he believed the group entered the abandoned mine to look for scrap copper to sell.

“It’s worth money,” he told the network. “A couple of years ago it was almost $4 a pound. You could make $1,000 a day.”

Search and rescue crews had been hunting for the missing amateur explorers since early on Sunday, pumping water out of the mine and pumping in fresh air with large fans.

The West Virginia National Guard assisted local and state agencies, the office of Governor Jim Justice said.

“All West Virginians who are driving, riding ATVs, or hiking near abandoned mines please stop entering the abandoned mines,” Justice said on Sunday.

“This is extremely irresponsible behavior that puts our first responders and mine safety crews in unsafe situations when they should be focused on ensuring safety at active mines.”

In 2010 a coal mine explosion in the area killed 29 people in the worst such U.S. disaster in four decades.