SCHERERVILLE, Ind. (CBS) — Shots were fired overnight Friday into Saturday at a house party in Schererville, Indiana, leaving a 15-year-old girl wounded in the back.

What happened next is what confuses investigators.

The girl’s friends did not call 911, but instead took her to the Taco Bell in nearby St. John, Indiana.

An ambulance picked up the girl at the restaurant. The girl was later airlifted to the University of Chicago Medical Center for advanced care.

The girl’s name and condition are not available, but we are told she was a student at Lake Central High School.

Authorities still are not sure why the girl’s friends did not call 911 sooner.