LEADVILLE, Colorado — The fiery explosion of a 50,000 square foot industrial complex Friday in Leadville put five people in the hospital.

One person with facial burns was in critical condition, and — contrary to previous reports — weather conditions prevented a helicopter from taking the person to a Denver hospital, said Marc Burdick, interim director of Summit County Ambulance Service, which was called in for assistance.

A Summit County ambulance took the burn victim from St. Vincent's Hospital in Leadville to University Hospital in Denver, he said.

The structure at 501 U.S. Highway 24 that exploded and burned at about 3:15 p.m. Friday housed industrial businesses including an automotive repair shop, a masonry business and a towing business.

Summit County ambulance set up a firefighter rehabilitation unit in a nearby business, where 35 firefighters were treated in cooperation with American Red Cross, Burdick said.

“Leadville's about 10,100 feet, and some of these firefighters were coming from Buena Vista where [elevation is about] 7,000 feet,” Burdick said. “We saw quite a few of them come through.”

One firefighter was taken to St. Vincent's for smoke inhalation.

Summit County Ambulance Service was on scene until about 11:30 p.m.

Agencies from Lake County, Copper Mountain, Eagle River, Salida and Chaffee County also responded to assist.

The cause of the explosion and fire is under investigation.

— The Denver Post contributed to this article.