MILWAUKEE (AP) — The Milwaukee County Transit System says an alert bus driver rescued a young child found wandering barefoot on a freeway overpass in frigid temperatures.

MCTS says the lost boy, who was less than a year old, was wearing just a diaper and onesie when driver Irena Ivic spotted him Dec. 22 along her route in Milwaukee. Transit video shows the boy toddling down the overpass. Ivic stopped her bus, ran across the street, picked up the crying child and carried him to the bus. As Ivic called for help, a passenger gave up her coat to keep the boy warm before police and firefighters arrived. Authorities say besides being cold and frightened, the youngster was OK.

Police say the child had been left outside by his mother who may have been suffering from a mental health crisis.