Yesterday's theft of a SFFD ambulance and subsequent police chase and crash has investigators scratching their heads as to just how, exactly, the thief managed to drive off with the vehicle.

In conversation with ABC 7, a spokesperson with SFFD explained that starting those things up isn't a simple as turning the key. "You have to push a button, use your foot on a brake, and move the key into the drive position in order to put the transmission into a functioning drive position," SFFD's Jonathan Baxter explained to the channel. "So that's a lot of feature for somebody off the street to know."

Apparently the ambulances are set up in a certain way that makes them difficult to steal — even if left running there is no clearly marked way to put them into drive. "So this is a very rare occurrence first of all, this doesn't happen every day," San Francisco police Officer Carlos Manfredi explained to ABC 7.

And yet.

It all started yesterday when two paramedics responding to an emergency call left their ambulance parked outside of the Ambassador Hotel at 55 Mason Street. They went inside to treat a patient, but when they returned outside at roughly 8:00 a.m. the ride was gone.

Police quickly tracked the stolen ambulance using a tracking feature in the ride, the Chronicle reports, and were soon in hot pursuit across the Bay Bridge. Attempting to take a quick exit at Treasure Island, the woman driving the ride crashed it — she reportedly climbed out around 8:10 as it was bursting into flames.

It is not clear at this time if the doors to the ambulance were locked, or if it was left running, but as the driver's side window was broken investigators think the thief may have smashed the window to gain entrance to the car (or it could have just broken in the crash).

The $225,000 ambulance was severely damaged by the crash and fire. The woman, taken into custody, was not seriously injured.

Previously: Stolen Ambulance Wrecks, Catches Fire On Treasure Island Following Police Chase