LA CROSSE, WI -

The La Crosse Fire Department has released the cause of the fire at Trane Company on Wednesday, September 11.

A contractor on site was doing demolition work at Trane Company’s technology building when the fire started, fire fighters said Monday.

The contractor was doing "hot work," cutting metal and that started a section of insulation on fire around 6:45 a.m. No one was injured.

Trane Company does not know how much damage the fire caused.