The viewer who shared this video with ABC7 news says she first called 911 at 7 p.m. Tuesday.
She says she called again about 15 minutes later when there was still no one there.
Finally she says she went to the fire station around 7:30 p.m. and when she returned the children had gone inside.
The Vallejo Police Department tells ABC7 it's investigating why the 911 call wasn't prioritized.
They plan to follow up with the parents to find out how the children got on the ledge in the first place.