The parents of two Bronx toddlers killed last year after a radiator exploded in their apartment, fatally burning the children, are suing the city.

According to court documents, they filed a lawsuit in September in Bronx State Supreme Court.

The suit accuses the city of negligence by ignoring dangerous conditions at the Hunts Point building and at other so-called "cluster sites," locations where landlords run homeless shelters.

The lawsuit also blames the owner of the building and the Bushwick Economic Development Corporation for the explosion.

Danielle and Peter Ambrose lost their 1- and 2-year-old daughters, Scylee and Ibanez, Dec. 7 last year after the radiator's steam filled the room and severely burned the children, who later died from their injuries.

The case put a spotlight on the city's use of "cluster sites."

The family says the explosion was preventable, because the building's owner had prior notice about the dilapidated conditions of the radiator.