David Hamilton, 37, died late Tuesday and Arnold Peters, 57, died early Wednesday, both at Vanderbilt University Medical Center in Nashville, Tenn. Jimmy Lemmings, 42, died at the hospital Sunday.
Altogether, 44 people were taken to hospitals after the explosion and fire Thursday at CTA Acoustics. More than a dozen of the injured were transferred to other hospitals for treatment of severe burns.
Federal and state fire investigators finished their initial examination at the company, which makes acoustic and thermal insulation for the automotive industry. They concluded it started around a production line where mats of fiberglass and backing material are bonded by passing them through ovens powered by natural gas.
The company reopened Tuesday on a limited basis.