A baby girl sitting in a stroller was killed after plunging down an elevator shaft Thursday morning at a Brooklyn apartment building, police said.

A 911 call for medical assistance at about 10:30 a.m. led officers to the upsetting discovery of a 6-week-old girl unconscious atop a stalled elevator eight floors below the opening in the shaft.

The mother of the baby told police that she pushed the stroller into the shaft, thinking the elevator was there, CBS News reported. Mother and child were on the 23rd floor of the building in the Sea Gate neighborhood.

The baby, named Areej Ali, was taken to Coney Island Hospital and pronounced dead.

The distraught mother of the infant was also taken to the hospital, police said.

The building, the Sea Rise apartment, has been the subject of numerous complaints about out-of-service elevators since January 2015 through as recently as last month, according to city records. The building currently has 50 open building code violations, including four elevator violations, the Daily News reported.