A Knox County trucking company faces a fine of more than $25,000 after one of its employees suffered fatal burns in a 2016 late-night explosion.

Records obtained by 10News show the Tennessee Department of Labor and Workforce Development is citing R & L Carriers Shared Services LLC for five "serious" violations. Fines total $25,600.

Mechanic Joseph Mack died Oct. 17, 2016, at Vanderbilt Medical Center after suffering burns over 90 percent of his body in a blast about 1:50 a.m. that day. Mack was a trailer mechanic at the business at 5004 N. National Drive.

The Tennessee Occupational Safety and Health Administration investigated the blast.

An R & L representative in Knox County said Wednesday the carrier would have "no comment" about the investigation and fines. The corporate headquarters is in Ohio.

The company is working on a settlement agreement with TOSHA, according to the state department.

Related: Worker dies after blast at Knox firm

After an investigation, state authorities cited R & L for among other things storing too much flammable liquids at the shop as well as improperly storing it.  An inspection also found the carrier failed to take adequate precautions to ward against the ignition of flammable vapors, according to records.

Records show the state's report and fine summary is dated Feb. 3 with fine payment to be submitted by March 5.

Mack was working in the mechanics shop, about 9,000 square feet in size. He was alone at the time.

He told authorities on the scene after the blast that he was working on trailer lights when he heard a noise and went to investigate. Mack then suffered critical injuries when there was an explosion in the shop.

"The victim explained to the fire marshal while in the ambulance that he heard a hissing noise and walked to some 55 gallon drums that exploded in fire" an investigation summary states.

Other employees also described hearing a boom before fire broke out.

Several drums were in the pre-fab metal building, including one containing a diesel anti-gel, which is flammable. Workers used the anti-gel as an additive to the diesel fuel on site.

Vapors from the anti-gel could have ignited because of exposure to static shock, heat or a hot surface, the report showed.

The carrier's maintenance shop was considered structurally unsound after the fire. The county fire marshal looked into the blast and fire, and state authorities used the county's fire marshal report in its investigation.

Authorities put the estimated fire loss at $500,000, records show.