HARLEM — Normally Kenroy Watson, a licensed master plumber who owns Watson Plumbing on St. Nicholas Avenue, gets one or two calls a day about possible gas leaks.
But the day after an East Harlem gas explosion leveled two buildings at 1644 and 1646 Park Ave., leaving eight people dead and others still unaccounted for, Watson, 53, received 10 calls about gas leaks.
What he saw has him worried.
One person had suspected a gas leak for weeks but waited until Thursday to call. In another home, Watson smelled gas the moment he stepped through the door. And many decrepit gas lines and connections are visible inside Harlem houses and multi-family buildings.
"I deal with it every day. In many buildings I visit, the gas lines are old and they need to be repaired," he said. "I'm surprised that it takes an explosion for people to be aware."
While the cause of the deadly explosion is still under investigation, it is drawing attention to the city's aging infrastructure.
Earlier this week, the Center for an Urban Future issued a report saying the city's infrastructure needs $47 billion worth of work over the next five years just to bring it up to a state of good repair.
The city’s gas mains are an average of 56 years old, according to the report. The distribution system had 5,835 leaks in 2012, and 60 percent of Con Edison's gas mains are made of cast iron or unprotected steel, which are outdated and prone to leaks, the report said.
"Under the Bloomberg administration, there was a promise to focus on building new schools and parks and to focus on new infrastructure," said Jonathan Bowles, executive director of the Center for an Urban Future. "The city of New York needs to focus attention on fixing existing infrastructure."
Mayor Bill de Blasio acknowledged the city's infrastructure issues at a City Hall press conference Thursday.
"Areas with old or vulnerable infrastructure describes a lot of New York City, honestly," de Blasio said, calling New York's aging systems "a fundamental challenge for New York City and any older city."
The mayor criticized the "dynamics of our national government," which have lead to a "lack of support" for infrastructure improvements," he said.
"The broader infrastructure challenge is something we address every single day with the resources we have, but that is a tough battle, given that we are not getting some of the support that we deserve," the mayor said.
The age of the city's housing stock also poses problems. The buildings that collapsed were older, city officials said.
Warren James, head of East Harlem-based Warren A. James Architecture, said he's not surprised by the number of building accidents in Harlem in recent years given the age of Harlem's housing stock and its infrastructure, combined with the renewed interest in living here.
"This could be the tip of the iceberg," said James.
Watson said 80 percent of the buildings he works on are 80 years old or older.
In Central Harlem, Harlem Tourism Board executive director Syderia Chresfield said a near tragedy in her neighborhood made her more vigilant.
"When I hear anything that could be a danger to the public, I will call anyone under the sun to make sure it's taken care of," she said.
A brownstone on 123rd Street in Mount Morris Park collapsed on May 4, 2012, after neighbors had reported that the building was not sound.
"It was quite a blessing that when that building fell, no one was in it and around it," she said about that collapse.
De Blasio urged city residents to immediately call Con-Edison or 311 any time they smell gas.
Watson said he hopes the East Harlem tragedy makes the city, homeowners and landlords more aware of infrastructure dangers.
"I hope people remember this," he said. "People are scared now because they don't want what happened yesterday to happen to them. This is nothing to play with."