Authorities in Coeur d'Alene, Idaho, shared updates on their investigation after a suspect ambushed firefighters on the job.

The man who shot dead two firefighters and wounded a third after setting a blaze near a popular mountainside trail in Idaho was described by authorities on Monday as a young transient whose motives remained a mystery a day after the attack.

Three victims were transported to Kootenai Health, though two were dead on arrival, according to hospital spokesperson Kim Anderson. One of the deceased was a firefighter from the Coeur d’Alene Fire Department and the other was a firefighter from Kootenai County Fire and Rescue.