OAKLAND, Calif. -- An armed man burst into the emergency room staff of Oakland Children's Hospital early Friday, pulling out a gun and threatening a staff member before surrendering to police and security officers, authorities said.

Cottrell Broadnax, an Oakland resident, was arrested on suspicion of carjacking, false imprisonment and possessing a firearm as an ex-felon, Oakland police Officer Jeff Thomason said.

Chief Nursing Officer Nancy Shibata told KTVU the incident began at 3:15 a.m. when a man ran into the hospital.

“He just ran into the front door,” she said. “He was disoriented and appeared to be impaired. He ended up pointing a gun at a staff member.”

She said in those early chaotic moments, the staff members tried to remain calm.

“Security called OPD, they quickly responded and the whole incident was over in about eight minutes,” she said. “It was a very quick event. The staff interacted with him. He was impaired and seemed to need help… I’m proud of the way the staff reacted.”

Officers quickly responded to the hospital at about 3:30 a.m., and Broadnax surrendered after police formed a perimeter of patrol rifle officers, Oakland police Officer Holly Joshi said.

Witnesses told KTVU that once Broadnax was confronted by police, he did not resist.

He kept telling the officers – “Don’t shoot me! Don’t shoot me! I gave up! I gave up!” the witnesses said.

Police said they did not know the motive and that the incident was under investigation. Shibata said the gunman was not known to the hospital staff.

“I don’t think there was any (relationship between the female worker and the gunman),” Oakland police captain Darren Allison said.

The emergency room – one of the main Bay Area trauma centers for children – quickly returned to normal operations.

"It all happened really fast," said hospital spokeswoman Erin Goldsmith, who said only eight minutes elapsed between when Broadnax entered the emergency room and when Oakland police apprehended him.

As for the nurse held hostage by Broadnax, Goldsmith said "she really responded admirably and professionally."

While Goldsmith said the response time of police and the hospital's internal security was appropriate, the hospital was taking measures to ensure safety in the future.

"We're still reviewing what happened and evaluating what worked," she said.

Broadnax, a 49-year-old transient, also reportedly jumped on the hood of a woman's car at a nearby gas station just prior to the hospital incident, Thomason said.

At 3:13 a.m., police received a report about a man who jumped on the hood of the woman's car at a gas station at the intersection of 47th Street and Martin Luther King Jr. Way, Thomason said.

The woman called police, and before officers arrived, the man fled on foot and ran into the hospital minutes later, according to Thomason.