A 3-year-old boy was critically injured when he fell three stories from the window of his Queens home Thursday morning, police said.

The tot tumbled out of a sixth-story window around 10:30 a.m. at a condo building on 38th Avenue near Union Street in Flushing and landed on a third-floor canopy.

The building’s super said the child landed on the roof of a glass structure that reaches up to the condo’s third-floor and houses an adult care facility.

His mother was in the kitchen cooking and his brother was watching TV, when he made his way to the window, pushed the screen out, and fell, the super and police sources said.

The mother had been tending to a bed-ridden relative, police sources said.

Neighbors said they heard her frantically rushing to grab her baby from the third-floor canopy before she called the authorities.

“I heard a woman knocking on people’s doors very fast, she was upset, saying ‘my son fell out of the window,’” said a 25-year-old woman named Eva who lives on the third-floor.

A neighbor on the seventh-floor who didn’t want to be named, said the mother lived in the apartment with her three “lovely” children and their elderly grandfather.

The child was rushed to Long Island Jewish Medical Center, an FDNY spokesman said. He was awake and responsive when he was taken away from the scene and his condition was later updated to stable, officials said.

There didn’t seem to be window guards on any of the apartments.

Additional reporting by Ben Cohn and Larry Celona