Allmendinger died in the line of duty on Saturday, October 19. Gallatin County Sheriff Brian Gootkin said that Allmendinger and Deputy Ryan Jern responded to a call for a welfare check of a driver who was stranded on Fairy Lake Road in the Bridger mountain range. The roads in the area were very slick and covered in snow, and their patrol vehicle began to slide backwards. As the vehicle was sliding, Allmendinger got out of the vehicle and somehow got trapped underneath it. Jern attempted to provide immediate first aid, but was unable to save Allendinger.