Three young children were injured Monday morning after a raging blaze broke out in their Bronx apartment building — where the 6-year-old, 3-year-old and 1-year-old girls had been left alone, cops said.

Firefighters responded to the fire at 783 Burke Ave. around 9:30 a.m. and removed the three girls, who suffered smoke inhalation. They were taken to Jacobi Hospital and were expected to survive, cops said.

Video of the fire shows the entire top floor engulfed in flames.

The girls’ mother told cops she left them alone because she had to take a relative to the hospital and didn’t want to take them with her, police said. The father was at work.

Both parents were being questioned by investigators and could face charges, police said.

“It’s an unfortunate chain of events,” a police spokesman said.

The FDNY said fire marshals determined the cause was electrical — building wiring — and that a smoke alarm was “present but not operational.”

The city’s Administration for Children’s Services is probing the incident, a rep said.

“Our top priority is protecting the safety and wellbeing of all children in New York City. We are investigating this case,” a spokesman said.