But the collapse is just a symptom of a larger problem on Glenmore Avenue.
When L&I officials got to the scene, they identified at least 16 other homes as unsafe or imminently dangerous - on that block alone.
"We're trying to take a more proactive approach," Mulderig said. "We're going to start taking a look at entire blocks."
L&I scrambles year-round to demolish hundreds of blighted homes before they collapse, but the list of imminently dangerous buildings keeps regenerating. At least eight buildings unexpectedly collapsed in February and March.
The Glenmore Avenue rowhouse that collapsed Sunday night had received dozens of L&I violations dating back to 2006. Mulderig said L&I had not been able to reach the owner yesterday.
"The owner happens to be an LLC that only has a P.O. box," he said. "That makes it very difficult for us."
Thomas Goldberg, 60, a lifelong resident of the block, said he believes that the Amtrak trains running directly behind the homes have caused damage over the years. His porch roof is partially caved in.
"The railroad did all this. No doubt about it," Goldberg said, as he pointed down the street to a row of homes with fluorescent orange L&I violations on their doors. "It's like a rocket going by, and your whole body is shaking."
Many of the homes, however, are abandoned. Mulderig said neglectful property owners, some of whom don't even live in the area, are a major cause of the city's blight problem.
"We keep stressing that people need to repair their properties," he said. "Maybe people will start listening."
About 90 minutes after Mulderig spoke, a building on Sydenham Street near York in North Philly partially collapsed. No injuries were reported.
- Staff writer Vinny Vella
contributed to this report.
On Twitter: @wbender99