Lt. Jay Ringgold, a fire department spokesman, said the man called 911 about 9:30 p.m. to report the fire and said he was in fear of his life.
The fire, at the former distillery buildings in the 7100 block of Sollers Point Road, was not under control until about 1:30 a.m. Sunday and escalated to three alarms, Ringgold said. Some embers spread to roofs on buildings elsewhere, but those blazes were extinguished.
The man was taken to the Maryland Shock Trauma Center in serious condition, and no update on his condition was available Sunday.
Part of the roof and interior of the building collapsed, Ringgold said. Several significant fires have been reported in the old Seagram's buildings, which are vacant, in the past few years.
The distillery, which was converted to make other forms of alcohol during the two World Wars, has been considered for revitalization efforts by county officials with plans that it might be used for condominiums or stores.
It's unclear what the man was doing inside the building at the time of the fire, and the cause of the blaze is under investigation, Ringgold said.
"It's a locked, closed facility, and no one should have been in the building at that time," he said.