PLEASANTON, Kan. — A volunteer Linn County, Kansas, firefighter has died after he was injured in a structure fire earlier this week.

Joshua Haynes, a firefighter with the Linn County, Kansas, Rural District 1 Fire Department, suffered life-threatening injuries Monday night while battling a fire at the Carpenter Chiropractor Clinic in Pleasanton, Kansas.

Officials previously said he was one of the first firefighters to make entry. Investigating agencies have not provided any information at this time on how Haynes was injured.

Other firefighters rescued Haynes and provided aid until he was taken by helicopter to the University of Kansas Health System.

Haynes died Wednesday, according to the Bureau of Alcohol, Tobacco, Firearms and Explosives. He leaves behind three children.

The ATF and Kansas State Fire Marshals Office are still investigating the cause of the fire. The ATF said Tuesday that no foul play is suspected.