KINSTON, N.C., Jan. 29 -- An explosion followed by a spectacular fire destroyed a North Carolina medical devices factory during the afternoon shift today, killing at least three people and injuring dozens, officials said.

There were about 75 workers inside the West Pharmaceutical Services plant in Kinston, N.C., at about 1:30 p.m., when the sudden blast ripped off the roof, blew out the doors and filled the sky with billowing black smoke, according to deputy city manager Phil Robey.

An intense fire spewed acrid chemical fumes into the winter air. After several hours of battling the blaze, firefighters using foam retardant had contained it to a corner of the plant by midnight. Authorities did not know what caused the explosion.

There were conflicting reports on the number of dead throughout the day, but late tonight Deral Raynor, chief of the North Lenoir Fire Department, confirmed that three people had been killed. Fifteen survivors were hospitalized with serious injuries, including head trauma, severe burns, broken bones and smoke inhalation.

Although Kinston police reported that at least 100 workers had not contacted their families by 3:30 p.m., Robey said fewer than 10 others were still missing tonight, as company officials combed records and tried to contact relatives. Dozens of other workers suffered minor injuries in the blast, which was felt 20 miles away.

"I heard the explosion two miles away, and loud," Robey said. "And the magnitude of the fire was just enormous. Obviously, in a town this size, something like this touches everyone."

Kinston is a city of about 24,000 located along the Neuse River, about 75 miles southeast of Raleigh. It was founded as an agricultural community in 1740 -- it was then known as "Kingston," but dropped the "g" to keep its loyalties clear during the Revolutionary War -- and developed a strong textiles base after the Industrial Revolution.

In recent years, it has depended more on manufacturers such as West, which produces syringe stoppers and intravenous tubing in an industrial park at the edge of town. Hurricane Floyd left most of the city underwater in 1999, and Kinston was hurting again during the recent economic downturn.

"We've been trying to rebuild ever since Floyd," Robey said. "We've been trying to pick up the pieces."

But today may have been Kinston's deadliest day since a Civil War battle in 1862 left more than 600 dead. In addition to the dead and missing, there were seven victims with severe burns transported to the North Carolina Jaycee Burn Center in Chapel Hill.

"We are seeing extensive burn injuries to all patients, as well as injuries to internal organs and orthopedic injuries as a result of the massive explosion," physician Cherri Hobgood told WRAL-TV. "One of the main challenges is this horrible weather. The patients have not only suffered a devastating injury, but many of them will be cold and chilled."

Witnesses to the blast described equipment and fireballs and even two 800-foot water towers hurtling through the sky, which quickly turned black with smoke.

Dana Rouse, a waitress at Ham's Restaurant in Kinston, said "There was like this big boom. The whole building shook. A lot of people ran outside to look."

"It blew the roof off a good 400 feet down the road," witness Jack Lambert told CNN. "It caught all the woods on fire."

Nannie Sue Winborne and Jerry Nethercutt told the Kinston Free Press they were working in the plant at the time of the explosion. "It was scary," Winborne said. "I was just hoping for a way out."

"It went black, and everything started falling," Nethercutt said.

The Occupational Safety and Health Administration cited the plant, which was opened in 1975, for numerous safety violations after a routine inspection in October, and fined the company $9,075 after an informal settlement three weeks ago. But Robey said that as far as he knew, West had been a good corporate citizen, bringing 225 jobs to the area.

"It's just the kind of employer you want to have," he said. "The immediacy of this hasn't hit us."

Grunwald reported from Washington. Researcher Mary Lou White contributed to this report.

Firefighters battle a huge blaze at the West Pharmaceutical Services plant in Kinston, N.C., after an explosion. Rescue personnel search behind the West Pharmaceutical Services plant for victims.