David Lindsey, Robert Evans, injured, airlifted to hospital, after they are burned by molten aluminum at the Kobe Aluminum Automotive Products plant in Bowling Green.

Molten aluminum burned the legs of two men about 1:30 p.m. Tuesday at Kobe Aluminum Automotive Products.

Both employees, David Lindsey and Robert Evans, who are operating technicians in the SB Building in the rear of the Kobe property, were wearing required personal protective equipment and fire retardant uniforms, corporate officer Greg Head said.

“The call came in that there was an explosion at Kobe Aluminum with two people injured,” Bowling Green Fire Department spokeswoman Marlee Boenig said.

When firefighters arrived at 525 Central Ave. in the industrial park, there was no fire, Boenig said. Instead, she described it as an industrial incident.

Within minutes, the two men were loaded onto medical transport helicopters and flown to Vanderbilt University Medical Center in Nashville, Head said.

Lindsey was treated and released, while Evans is listed in stable condition, hospital officials said.

Fellow employees had applied burn gel to the injured men’s affected areas. Burn gel helps prevent tissue damage. The company immediately contacted the injured men’s family members, who got to see the men before they were airlifted out from a field in front of nearby Stoody Co.

“A full internal investigation is underway to completely understand why the event occurred,” Head said in a release.

During an interview Tuesday night, Head explained that water is the usual suspect in incidents of this nature.

“In most cases, something like this when you are talking about molten aluminum, there is usually water involved somehow. The guys are working and trying to find out for sure. The reason that can be an issue is because water has a 2,000 times expansion rate, so one ounce of water becomes 2,000 ounces when it is super heated. It has not been confirmed” that this is what caused Tuesday’s incident, Head said.

“It’s what the industry calls a thermal pop,” Head said. “Molten aluminum is extremely stable. The only way it will move out of its container is if expansion pushes it out. It makes a noise similar to a firecracker. It makes a pop, that’s why they call it a thermal pop.”

Aluminum doesn’t explode, Head said.

Kobe, a Japanese-owned plant, produces aluminum for the automotive industry. There are about 310 employees at the Bowling Green plant, Head said.

“We’re like a big family out there at the plant,” Head said after visiting with the men at Vanderbilt. “No one is any more important than anyone else.”

He said the men were in “good spirits” Tuesday night.