CHICAGO (Sun-Times Media Wire) – A woman was sexually assaulted Sunday night during the Foo Fighters concert at Wrigley Field.

The 23-year-old woman was standing in line for food about 9:30 p.m. in the 1000 block of West Addison when a man groped her, according to Chicago Police. She left the line and went into a port-a-potty.

The man followed her and also entered the port-a-potty before she could lock the door, police said. He then sexually assaulted her.

The woman was taken to a hospital after the assault, police said.

The suspect was described as a 5-foot-9 white man between 40 and 50 years old, police said. He was balding with brown hair.

No one was in custody yet, as Area North detectives investigated.