E281 was dispatched to the 5300 blk of Riverdale Rd for the report of “smoke in the building”. On arrival, Companies found a 6 story high rise with nothing evident from the alpha side. With initial reports for smoke on fifth floor, crews started making their way up. A fire was then located in the trash room on the Bravo side, where E281s crew redeployed the attack line as back up. Units operated for approximately 1hr 30min before returning to service.