The two massive explosions occurred about 2:45 a.m. in the Amodel unit of the BP Amoco Polymers plant at Tobacco and Clanton roads, according to Pam Barbara, site services manager.

Two workers were killed in the blasts, and a third died later at Medical College of Georgia Hospital.

Mrs. Barbara identified the dead as Heinrich Kohl, 25; George Sanders, 42; and John Rowland, 35.

The federal Occupational Safety and Health Administration sent two compliance officers to investigate the explosions, said Cindy Coe, the agency's regional administrator in Atlanta. A third investigator, with expertise in explosions, will arrive this afternoon from the agency's national office in Washington, Ms. Coe said. The agency must complete its investigation within six months, she said.

``They will be trying to find out what happened and assessing whether there were any issues in violation of our regulations,'' she said.

An internal investigative team from Amoco Polymers and an inspector from the Georgia Department of Labor will also look into the blasts.

The federal agency can issue fines of up to $70,000 if the company is found in severe violation of federal regulations or if it is found in repeat violation of regulations it has been cited for during the past three years, Ms. Coe said. The company was fined $622 in July 1997 for a ``serious violation,'' according to OSHA's Web site.

The explosions occurred simultaneously as workers were shutting down the Amodel unit - where employees fashion metal fasteners - for repairs, Mrs. Barbara said. The building where the explosions occurred was built in 1993.

``It's not unusual that it was being repaired,'' she said. ``It's a wear and tear thing.''

Plant officials said that Syltherm, a heat-transfer fluid that keeps pipes hot to prevent polymers from hardening, fueled the blaze. The workers had already flushed water through the pipes and were in the cool-down process when the explosions occurred.

According to Valerie Spratlin, spokeswoman for RuralMetro ambulance, Mr. Kohl and Mr. Sanders were dead when paramedics arrived, and employees were administering cardiopulmonary resuscitation to Mr. Rowland. He died at MCG of ``massive trauma,'' Ms. Spratlin said.

``It's a very, very tough time for all of us,'' said Scott Savage, plant manager. ``It's a very tragic event, and a lot of people are not doing very well right now.''

Counselors and a pastor have been brought in to help employees cope with tragedy, Mrs. Barbara said.

By 8:15 a.m., firefighters had extinguished the blaze and reopened roads near the plant for workers arriving for the morning shift.

Production at the plant has been temporarily shut down. Employees were expected to come to work, however.

More than 200 people work at the plant, and about 25 were working when the explosion occurred.

This is the first time anyone has died in an industrial accident since Amoco took over the plant in 1988, Mrs. Barbara said.

``It's just awful,'' she said. ``We practice for this, but the gravity of it when it actually happens is tremendous.''

The plant, operated by BP Amoco Chemicals Inc., produces high-performance plastics designed to withstand high temperatures and used in such products as auto parts and hospital equipment. The chemical company, a division of oil giant BP Amoco, also has a research-and-development center at its U.S. headquarters in Alpharetta, Ga.