Updated

A 9-year-old girl broke both her ankles after falling 12 feet through an open manhole and being stranded for an hour before a passerby heard her yells for help.

Grace Knox was on her way to Southside Elementary School in Buffalo, N.Y., around 7:30 a.m. Tuesday when she suddenly fell into the manhole that was missing its cover, WIVB-TV reported.

Buffalo Fire Capt. Daniel O’Leary said the girl was found in “about a foot or two of water.” Rescuers pulled her out at around 9 a.m., after the passerby heard the girl calling for her mom.

Officials discovered the manhole cover about 5 feet away, but can’t explain why it had been removed.

The girl was treated at a local hospital.

The Associated Press contributed to this report.