New York City investigators posing as apartment hunters discovered dozens of spaces that had been illegally converted into apartments and had dangerous living conditions such as inadequate fire escape routes.
Property owners often illegally convert rooms and buildings into spaces that are presented to renters as apartments but do not meet city building code.
Mayor Michael Bloomberg's administration on Thursday detailed the sting operation it began last spring to crack down on the practice, which officials said is common in this city where rents are sky high. More than 100 violations were found in 62 apartments inspected.
Bloomberg said there are estimates that "many many thousands" of people live in illegally converted spaces.
Investigators wearing hidden cameras found hazardous conditions including illegal gas, electrical and plumbing work, divided rooms with no ventilation, and sleeping quarters near boilers and furnaces.
The most common violation was not having enough ways to escape fire. Many spaces had only one way in and out, which falls short of meeting code requirements.
"Illegal conversions can kill," the mayor said. "They pose a potentially deadly menace to people across our city, to people who live in them and to the people who live near them, and also to our firefighters who may find themselves dangerously boxed into rooms with no exits when they've been battling fires."
The fire department said fires in illegal conversions have killed seven people this year.
This month, three firefighters were injured in the Bronx while rescuing a woman and a child from a fire in a cellar that was illegally divided into living spaces.
Earlier this year, five people died in a fire that erupted in an illegally converted building in Brooklyn and spread to a second illegal conversion next door.
And in 2005, two firefighters fighting a fire in an illegally converted Bronx building died after jumping from a window to escape the blaze.
City officials said they went undercover for the probe because it is difficult to investigate illegally converted apartments. Landlords and property owners often deny access, and it can be nearly impossible to obtain warrants, they said.
So the city sent undercover investigators to examine apartments featured in online rental listings.
Of the 62 apartments inspected, 54 had illegal living conditions. The city issued vacate orders to 33 apartments where conditions posed immediate safety threats; the remainder were slapped with fines.
More than 100 violations were issued, with penalties ranging from $6,000 to $25,000.
To resolve the violations, property owners must correct the illegal construction work and submit certificates of correction or sworn affidavits to the city explaining how the problems were fixed.