CHICAGO (CBS) — A 17-month-old girl was killed early Sunday, when two dogs got loose during a July 4th party in Joliet, and at least one of the dogs attacked her while she was in a playpen.

Joliet police said, around 1:30 a.m. Sunday, officers responded to a home in the 1800 block of Cumberland Drive, for a report of a 1-year-old being bit by a dog.

Officers learned the parents of a 17-month-old girl were attending a friend’s July 4th party, and had put the toddler in a playpen in an upstairs bedroom. Two pit bull mixes had been locked in the basement, but got out at some point during the night.

When the homeowner heard a noise from upstairs and went to investigate, they found one of the dogs biting the toddler. The homeowner was able to separate the dog from the toddler, and called 911.

The girl had suffered multiple bites throughout her body, and was taken to AMITA Health Saint Joseph Medical Center Joliet, where she was pronounced dead around 3:30 a.m., according to police.

The dog that bit the girl has been turned over to Joliet Township Animal Control.

Joliet police are investigating.