Authorities are investigating emergency response times after a deadly fire in Queens this past weekend.
The city Department of Investigation wants to know more about how ambulances were dispatched to the Far Rockaway home Saturday night.
Officials say two 4-year-old children died of smoke inhalation after flames broke out just before midnight.
Firefighters say crews arrived within minutes of a 911 call, but officials say an ambulance was not immediately dispatched.
Fire Commissioner Salvatore Cassano said he was disappointed to hear about a slow response time.
"Any time we have an operation and there's a possibility that something went wrong, I'm always dismayed," Cassano said. "We train very hard. Our job is to protect life and property, and we look at everything we do very critically."
A union representing EMTs is defending their response time, even as Mayor Bill de Blasio and other elected officials demand a review.