A D.C. fire department says an ambulance was taken out of service while on a run to the White House because it ran out of gas.

The Washington Times reports that the ambulance was left behind on the South Lawn when a motorcade left Thursday.

D.C. fire department spokesman Tim Wilson said Monday that the first-due medical responder to the White House ran out of gas, but another unit replaced it. He could not confirm whether the ambulance was on motorcade duty.

Wilson says an internal investigation is being conducted to determine whether the vehicle was properly fueled, but he says he does not know of any previously reported fuel gauge problem.