Four firefighters suffered minor injuries and a vocational building was severely damaged yesterday in an electrical fire at Lorton Reformatory's Central facility, according to officials from the Fairfax County Fire Department and the D.C. Department of Corrections.

Officials said that inmates at the medium-security prison remained orderly during the fire and that about 240 of them who are housed in four dormitories near the fire scene were evacuated without incident and taken to the facility's playing field.

Fairfax County police and fire officials said they were notified of the fire at 6:58 a.m., and firefighters entered the prison to attack the blaze eight minutes later. It took 65 firefighters about an hour to bring the two-alarm fire under control, they said.

County officials have complained in the past that District officials have not told them promptly of incidents at the city-run prison complex, but Fairfax police spokesman Warren Carmichael said that notification of yesterday's fire "seemed to go without a hitch."

About 20 police officers went to the prison and surrounded it while officers in a helicopter monitored the situation, he said, and "we never had any indication of any problems with the prisoners."

The fire was confined to a vocational building that housed the facility's culinary school, which has been the Corrections Department's most successful inmate training program. Numerous inmates from the program have gone on to work in the kitchens of some of the District's most exclusive clubs, and the program has been hailed for its low recidivist rate.

A spokesman for the D.C. Fire Department, which investigated the blaze, said the fire was started by an overheated motor in a refrigerator. Damage was estimated at $75,000.

Fairfax County Fire Chief Warren E. Isman said about one-quarter of the building, which also houses a bricklaying school and which is separated from the housing units by a fence, was damaged by fire, with smoke and water damage spread throughout the structure.

Wind blew heavy smoke into four dormitories near the fire, Isman said, and about 240 inmates were evacuated, some from the facility's dining hall, to the prison's playing field. Officers surrounded the inmates on the field, but there were no unusual incidents, they said.

Four firefighters injured in the blaze were treated for minor injuries at Mount Vernon Hospital and released, a spokeswoman there said.