Engine Co. No. 4 stretched on a working fire in the 200 block of Army Blvd. in 22º weather. Engine 4 checked out with heavy fire showing from the bravo and Charlie sides from the first floor of a 3 story with a basement single family dwelling prompting the box alarm to be filled out. Companies quickly and aggressively searched all 3 floor due to reports of people trapped, and located fire extending into divisions 2 and 3. Searches came back negative. Engine crews stretched 3 attack lines to bring the fire under control at the 30 min time stamp.