The incident happened in Park Slope, at Fifth Avenue and President Street.
The 2-year-old boy and his 59-year-old babysitter were walking by the Fifth Avenue Cat Clinic around 4 p.m. when the 16-foot-wide rolled-up gate and its frame came off the building and fell onto them.
The boy broke his leg and is listed in stable condition at Lutheran Hospital. The babysitter was treated and released.
Investigators from the Department of Buildings issued a failure to maintain violations to the building owners, but since the gates are not really a part of the building, the buildings department doesn't normally inspect them.
In May, a 12-year-old Brooklyn boy was crushed to death when he got caught in an electronic roll-up gate.
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