A 6-year-old girl was struck by a falling brick and left with a broken leg as she walked with her mom in Queens Thursday evening, cops and sources said.

The youngster had stopped to wave at her dad through a hole in a fence as he did construction work on a neighboring building — just as a piece of brick siding came tumbling down from a storage facility in Maspeth around 7:35 p.m., sources said.

She was hit by the plummeting brick “within seconds,” fell to the sidewalk, and screamed, the girl’s father, who wished not to be identified, told The Post.

“She get out from the car, she was on the sidewalk. It was quick, within seconds. She screamed; she was with my wife. It was really quick,” he said. “I don’t know exactly what happened.”

The blow left the girl with a cut on her head and a broken femur, which will require surgery, according to police and the dad.

“She was being carried by, I’m assuming, either her father or her guardian, and then they were just walking to the ambulance, and then I think the EMT individuals checked her out … So I’ve seen a cop here and all that. It’s kind of surprising, ” said neighbor and witness Hassan Hamid.

She was taken conscious and alert to Bellevue Hospital, where she was listed in stable condition.

The child’s father said his “focus” is on his daughter as she recovers from the freak accident in the hospital.

“They will do surgery, maybe today or tomorrow. They will put in some screws. The doctor said there is a big chance she’s gonna be ok,” the dad said.

“We have to just concentrate on my daughter. They’re going to see [when she’ll be released] after surgery. Hopefully in a day or two.”

Despite her injuries, he said his daughter is doing “OK”.

“She is reading a little, sleeping, they gave her painkillers, watching a little TV. She complains; she is in pain from her fracture. But she is ok. They keep checking her.”

“Thanks God that it isn’t anything big, no injury to the head. The biggest injury is to the leg, the leg, just below the hip.”