The cause of a deadly three-alarm fire in the Bronx Wednesday was caused by an electric scooter being charged, according to the FDNY.

A 91-year-old woman was killed in the fire at a Melrose apartment complex, and two others remain in critical condition.

MORE: Officials: 91-year-old dead, at least 12 others injured, in 3-alarm fire on Park Avenue

The FDNY released a statement today on Twitter, saying that fire marshals have determined the fire to be accidental and electrical due to an electric scooter being charged. They say a smoke alarm was present and activated.

A total of 12 people were injured, including a firefighter.

Over 130 fire responders were called out to respond to the fire.