“The unit apparently did run out of gas, but a replacement unit was put in its place,” D.C. fire department spokesman Tim Wilson told the paper.

The Washington affiliate of ABC News reported that the replacement ambulance arrived at the White House 19 minutes after the motorcade had already left.

It's the latest setback for the D.C. fire department, which has seen its ambulance fleet beleaguered by mechanical problems throughout the summer. Of the department's 94 ambulances — not all of which are in service — 67 required mechanical service over a one week period in July.