(Portland, OR) -- Officials say three fires have been intentionally set at the same building in Gresham in a period of 48 hours. The third fire took place around 5:30 yesterday morning at the building in the 18-thousand-500 block of East Burnside. Gresham Fire Battalion Fire Chief Jason McGowan told KOIN-TV transients have been known to sleep inside the vacant building. No injuries have been reported in any of the three fires.