'We never want to see this happen again': Mayor Barrett says investigation underway after 4-year-old left in tow lot overnight

Milwaukee Mayor Tom Barrett said Thursday police are investigating how a 4-year-old girl was left in a tow lot overnight after an officer apparently failed to notice her during a traffic stop.

The girl, whose mother was arrested on suspicion of drunken driving shortly after midnight Tuesday, was found crying in her family's van hours after it was towed to the city's lot.

"It is appropriate for there to be an investigation into this because it's troubling that the child was not discovered," Barrett said. "We never want to see this happen again."

The girl had been in the van about eight hours before a tow lot operator heard her crying.

RELATED:4-year-old spent 8 hours unnoticed in Milwaukee city tow lot after mother's drunken-driving arrest

"I've already spoken to the Police Department. They are conducting an internal investigation," Barrett said.

He added the city's Department of Public Works, which operates the tow lot, is also reviewing its procedures.

Barrett said he watched body-camera video of the stop.

"I think when the video is released, that's going to answer some questions and raise some more questions," the mayor said. "I'm going to let people decide for themselves based on that."

The girl's mother was pulled over around midnight by police on suspicion of drunken driving near South 39th Street and West Oklahoma Avenue. A 10-month-old baby was taken out of the vehicle, but the 4-year-old was not.

Vehicles should be "thoroughly searched" at the scene before being towed, under the Police Department's procedures.

The van was placed on a flatbed truck by the city's towing contractor and taken to the lot on Lincoln Avenue. At the lot, all vehicles are supposed to be inspected with someone from the lot getting on the flatbed to record vehicle identification and license plate numbers and using a flashlight to inspect vehicles.

The girl wasn't found until about 8:30 a.m. when she was heard crying.

The Fire Department was called to check the girl for exposure after eight hours in cold weather. It appeared the girl was OK but she was taken to a hospital as a precaution.

The temperature overnight Tuesday dropped to 18 degrees.

"Obviously as a dad, I'm concerned about this," Barrett said.