The break, which happened some before 4 a.m. on Garden Avenue between Sunnyside and Glendale Avenues, sent water flowing.
Resident Tristan Tsuji returned home at 3:45 a.m. and saw the flowing water. "I noticed that the water had been flowing out from underneath or front our stairs," he said.
"These are old houses a lot of them are on a water-based radiator system and we might be without heat for a few days."
City crews arrived after 5 a.m. to repair the break.