The Boston Police Department says detectives and the state Department of Children and Families want to know why it took the girl's parents almost five hours to call 911 to report their daughter missing Sunday.

Police say they found the girl on Olney Street around 4:45 p.m. after a good Samaritan called them to report a young girl gave her an even younger girl, about 2, who'd been wandering around Olney Street.

Police say: "The officers canvassed the area knocking on doors from Puritan Ave, to Geneva Ave. to Olney Street without any success in finding a parent/guardian for the child. The child was transported to the hospital for an evaluation but a parent/guardian has yet to be located.

The department says the parents called 911 around 9:40 p.m.