The fire happened Friday morning on Swinton Avenue in Throgs Neck.
A grandmother was killed and three others critically hurt.
The NYPD is looking into why it took a 911 dispatcher four minutes to get through to the FDNY.
Police say operator took the initial call at 3:45 a.m.
It was phoned in from Quincy Street, which is about a block away from the fire, and the caller didn't have the exact address of the fire building.
That 911 call lasted about 90 seconds.
Around 2 minutes after that, at 3:49 a.m., the 911 dispatcher called an FDNY dispatcher and gave her the information.
It took 4 minutes to get it to a dispatcher when normal protocol calls for electronic information to be sent right away.
Police say they're investigating why normal protocol was not followed.
Most of the flames were on the first floor, which briefly delayed firefighters from reaching the victims who were in the upstairs bedrooms.
One man and three women were pulled by firefighters from the building.
Ramon Velez, Jr. was one of four people pulled from the burning house overnight. Velez's 5-year-old granddaughter Reina and his 75-year-old mother in law were also hospitalized. But Velez's wife 55-year-old Ketty Lamarche died of smoke inhalation.
Velez, Jr. is the son of the late Bronx City Councilman Ramon S. Velez, Sr.
The father, Ramon S. Velez, was beloved by many Bronx residents in the 1970s and 80s, but derided by politicians like former Mayor Ed Koch.
The fire was put out in about a half hour.
The cause is under investigation.