Two ​firefighters were hospitalised, including a fire marshal who ⁠suffered a fractured temple and a brain ​bleed and was intubated, officials said.

The other ​firefighter was in serious condition but had shown improvement, officials said.

“This was a complex, fast-developing emergency,” New York Mayor ​Zohran Mamdani told reporters.

“First responders did what they ​always do: they ran towards danger so others could escape ‌to ⁠safety.”

Officials did not provide details about the person who died except to say it was a civilian.

A comprehensive investigation would begin once the fire ​was completely ​extinguished, Mamdani ⁠said.

Firefighters had responded to reports of a fire in a basement, and ​two workers trapped and were on ​scene when ⁠the explosion occurred, officials said.

The incident took place in the Richmond Terrace section of the borough of ⁠Staten ​Island, a part of New ​York City that is across the harbour from Manhattan.