Sacramento firefighters responded to a fire alarm at the federal courthouse just after 2 p.m. on Tuesday.

Fire crews made their way into the Robert T. Matsui Federal Courthouse, at 501 I St., after a fifth-floor fire alarm was reported at 1:58 p.m., said Battalion Chief Marc Bentovoja.

Three engines and one truck are at the scene. Bentovoja and 12 other firefighters are investigating the cause of the alarm.