Florida ? Explosions and fires at a chemical plant in Jacksonville killed four people, injured at least 14 and sent debris flying several stories into the air, fire officials and witnesses said Wednesday.

It was not clear what caused the explosions about 1:30 p.m. at the T2 Laboratories Inc. plant, which makes chemical solvents and fuel additives, said Tom Francis, a fire rescue spokesman.

The chemicals at the plant made the environment “incredibly dangerous for the first responders,” Francis said. “Explosions were generating all kinds of side brush fires and other kinds of blazes.”

Everyone at the plant was accounted for by Wednesday evening.

“Nothing there resembles a building,” Mayor John Peyton said. “It’s amazing when you see the scene that there wasn’t more loss of life.”

A board member and a six-person investigation team from the U.S. Chemical Safety Board was expected to arrive at the site Thursday morning to begin an investigation.