WASHINGTON (AP) – A District of Columbia police officer seriously injured in a hit-and-run crash had to wait at least 15 minutes for an ambulance from Prince George’s County because none were available in Washington.

The incident Tuesday night is stirring debate over staffing levels and response times. The heads of the police and firefighters unions called the lack of an ambulance unacceptable and inexcusable.

Deputy Mayor for Public Safety Paul Quander said Wednesday that he’s ordering an investigation to determine why there were no ambulances available.

Quander says 39 ambulances or paramedic units were supposed to be on D.C. streets. But a dispatcher was unable to find a free unit. The dispatcher requested help from Prince George’s County six minutes after the first 911 call. It arrived 18 minutes after the call.

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