A woman in a stolen ambulance led San Francisco police on a chase through the city and over the Bay Bridge onto Yerba Buena Island, where the fleeing driver lost control of the emergency vehicle and ended up in a fiery crash Tuesday morning, officials said.

The California Highway Patrol issued a Sig Alert and closed the Treasure Island eastbound off-ramp, along with two lanes of the Bay Bridge while police and firefighters responded to the chaotic scene that unfolded at the height of the morning commute, causing major delays.

The woman boosted the San Francisco Fire Department’s Medic 65 around 8 a.m. while paramedics were responding to a minor medical call at 55 Mason Street, firefighters said.

The paramedics left the ambulance running outside the Ambassador Hotel in the Tenderloin and when they returned with the patient, their emergency vehicle was gone, said Lt. Jonathan Baxter, a Fire Department spokesman. The patient was later treated at a hospital for a minor injury.

Police used a tracking system inside the vehicle to pinpoint the fleeing driver as she careened through city streets, slamming into several vehicles, said Officer Grace Gatpandan, a San Francisco police spokeswoman.

Officers caught up to the ambulance and pursued it over the Bay Bridge, where the driver took a sharp left onto the Treasure Island Road exit, where she hit a concrete barrier, police said.

The woman, who was not immediately identified, got out of the ambulance as it burst into flames around 8:10 a.m. She was not seriously injured and was taken into custody at the scene.

The San Francisco Fire Department released photos of the burned ambulance after a large plume of smoke was seen billowing from the island. There were no reports of injuries during the episode. The off-ramp onto Treasure Island was reopened around 10:15 a.m.

Evan Sernoffsky is a San Francisco Chronicle staff writer. Email: esernoffsky@sfchronicle.com Twitter: EvanSernoffsky