A 54-year-old man reported to be punching the glass doors of an east Santa Rosa office building died in custody Wednesday after suffering an unknown medical condition, police said.

The incident was reported just before 3 p.m. at a building on South E Street and Maple Avenue, Lt. John Snetsinger said.

Two officers sent to the location detained the man, who was not identified, after seeing him break a window, Snetsinger said.

During the investigation, officers noticed the man suffering an unknown medical emergency. An ambulance took him to the hospital, where he later died, the lieutenant said.

Because the death happened while the man was held by police, it will be investigated by an outside agency, in this case, Petaluma police, under a countywide fatal incident protocol for law enforcement.

You can reach Staff Writer Paul Payne at 707-568-5312 or paul.payne@pressdemocrat.com. On Twitter @ppayne.