A man has died of injuries suffered in an Indianapolis apartment fire this week that left four children ages 15 months, 3, 12 and 14 in critical condition, authorities said.

Raymond Diggs, 31, died Wednesday of thermal burns and smoke inhalation, and death was imminent for 15-month-old-old Leilani Rembert, who suffered smoke inhalation in Monday's fire, the Marion County Coroner’s Office said.

The girl was on a ventilator for possible organ donation, the office said.

INDIANA MAN, 4 CHILDREN HOSPITALIZED IN CARDIAC ARREST AFTER APARTMENT FIRE

Indianapolis firefighters performed CPR on the five victims and transported them to hospitals late Monday.

Diggs died Wednesday morning, Battalion Chief Rita Reith said.

The other children, who suffered cardiac arrest, remained in critical but stable condition at Riley Hospital for Children, Reith said.

Indiana local

A fire at an Indianapolis apartment left a man dead and four children hospitalized, with death "imminent" for the youngest. (Fox News)

The fire started on a couch late Monday in an apartment on the city’s far east side and was under control within a minute of firefighters’ arrival, Reith said.

CAUSE OF INDIANA HOUSE FIRE THAT KILLED STATE TROOPER, DAUGHTER REMAINS UNKNOWN

Burning couches can emit dangerous chemicals, and the victims may have been sleeping while the fire burned, she said.

How the fire started was under investigation.

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Diggs was the father of Leilani and the 3-year-old girl, WISH-TV reported. The 14-year-old and 12-year-old are boys.