Metro

Gate-crash horror

A nanny and a 2-year-old boy strolling hand-in-hand down a Brooklyn street were injured yesterday when an entire roll-down gate suddenly crashed down on them.

The freak accident took place on Fifth Avenue at President Street in Park Slope when the 16-foot- wide security gate broke loose from the building and toppled onto the duo at 4:15 p.m.

“I looked up and I saw it falling, coming at me,’’ the nanny, Nosrat Dezfoulian, told the Post after she was released from the hospital.

“The only thing on my mind was to save the baby. I tried to shield the baby, but I couldn’t.’’

The gate briefly pinned them both, but “strangers came running to me and lifted it off,’’ Dezfoulian said.

She suffered head injuries requiring stiches and staples to close; the toddler’s leg, she said, was broken in three places and he was undergoing surgery last night.

Dezfoulian’s “head was split open and gushing blood all down her face,” said a witness, Christine Castellano. “The boy’s leg looked crushed and bent in different directions.”

The child’s mother came running down the block to the bloody scene shortly after the accident.

“The look on her face was heartbreaking,” said another witness Bethany O’Grady, 22. “[She said,] ‘What’s happening? What’s going on?’ ”

Authorities were trying to figure that out.

A spokeswoman for the city’s Buildings Department said it appeared the gate’s “welding failed due to poor maintenance.”

Neither the building — which includes residences and the Fifth Avenue Cat Clinic — nor its owner has a history of serious violations, she said.

City inspectors on the scene issued a citation to the owner for failing to maintain the building.

Additional reporting by James Cahalan