SAN FRANCISCO (AP/CBS SF) — Five law enforcement and a tow truck driver hospitalized after possible fentanyl exposure on the Golden Gate Bridge have been released from the hospital, an official said Monday.

Four California Highway Patrol officers, a Golden Gate Bridge patrol officer and a bridge tow truck driver were exposed to a chemical substance believed to be fentanyl while attempting to aid the driver of a car who stopped Sunday on the San Francisco bridge, said CHP Officer Andrew Barclay.

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The CHP received a call at 11:45 a.m. Sunday describing a possibly impaired driver headed north toward the Golden Gate Bridge. Moments later, that driver crashed into a moveable median barrier at the toll plaza, blocking a lane there.

As San Francisco Fire Department personnel tended to the driver, who was unconscious, a CHP officer went into the crashed car to put it into “park” and prepare to move it to the Alexander Avenue off-ramp north of the bridge.

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At Alexander Avenue, the first CHP officer, plus another CHP officer and the tow truck driver, became incapacitated, apparently from fentanyl exposure, the CHP said.

“Very quickly those symptoms escalated and [the officer] became incapacitated,” said Barclay. “Fortunately there were other units on scene that were able to see what was going on requesting immediate medical response and began administering Narcan to him.”

During the subsequent investigation at Alexander Avenue, two more CHP officers and a Golden Gate Bridge Patrol officer began displaying symptoms of possible exposure and were transported to Marin General Hospital for treatment and monitoring.

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The suspect has been released from the hospital and was booked into San Francisco County Jail on charges of DUI and possession of a controlled substance.