DuShon Monique Brown, known for her role as Connie, Assistant to Chief Boden, on NBC’s Chicago Fire, died Friday. The Cook County medical examiner’s office tells The Chicago Tribune that Brown died shortly after noon at St. James Olympia Field Hospital. A cause of death is not yet known.

Brown had played the key recurring character since the series launch in 2012. “The Chicago Fire family is devastated to lose one of its own,” executive producer Dick Wolf said in a statement provided to Deadline. “Our thoughts and prayers are with DuShon’s family and we will all miss her.”

She previously recurred as Katie Welch on Fox’s Prison Break and recently guest-starred on Philip K. Dick’s Electric Dreams for Amazon.

Brown, a Chicago native, was a longtime theater actor before segueing to television, having performed at the Goodman, Victory Gardens, Lookingglass, Drury Lane, MPAACT and Pegasus Players in Chicago. Her other TV work also included guest spots on Empire and Shameless.

In an interview last year with the website Hidden Remote, Brown said that when she was first cast in the role of Connie on Chicago Fire, “my character didn’t even have a name. She was a noun. She was Secretary and it was a one-liner. What was exciting was [I] was auditioning for a Chicago show, but it was also the possibility that she could maybe develop into something.”