Meanwhile, residents and workers inside the perimeter were also disrupted by the day's events. Helicopters hovered ahead. Police were stopping vehicles to search trunks, as well as questioning some pedestrians. In some areas, police were knocking on doors looking for the gunman, described as a 40-year-old white man with long brown hair, clad in a bomber jacket and blue jeans.

LAUSD officials said the students were all safe and secure. There were some reports, though, of students going without food or being forced to urinate into trash cans.

That massive search area has caused headaches for thousands. At one point, nine schools with a combined enrollment of 9,000 students were under lockdown orders. By late afternoon -– long after school usually lets out -– some students remained stuck in their classrooms as anxious parents waited around the perimeter.

More than 350 officers from four agencies are combing the swath of the west San Fernando Valley, searching for a man who shot a Los Angeles Unified School District police officer after he was confronted in the midst of suspicious activity.

The seven square miles that police are scouring in Woodland Hills is one of the largest LAPD search areas in recent memory, police officials said.

Josh Morgan, 31, whose office is on Ventura Boulevard, said he and his colleagues tried to walk to lunch, but were turned back at the perimeter.

"We were able to leave the office, but made it about half a block down the street," Morgan said. Officers told them they wouldn't be able to come back. Instead, Morgan and his colleagues returned to work and ate potato chips and other snacks.

"People have their browsers open with live feeds of several local stations, and the boss has the TV on with news, but it's basically just been business as usual," said Morgan, who works at Click N Kids, which produces educational Web-based games. "We know something is going on outside. We can hear sirens and helicopters every once in a while."

At El Camino Real High School, the campus adjacent to the shooting site, 10th-grader Madison Handelman said police officers carrying large guns searched the gymnasium with dogs.

Katie Testo, an 18-year-old senior, said that SWAT teams were combing the hallways and that students were watching the news and waiting for word on when they would be released.

"We're really anxious and really scared because we don't know what's going on," Testo said.

Davood Khoshnood, who works in data information services at Northridge Hospital Medical Center, said his daughter Marjohn, 17, is a student at El Camino Real and had been texting him all day. He said she has been under lockdown, held without anything to eat for the last several hours.

"She's OK. She's taking it pretty good," said Khoshnood. "She's more concerned about the officer."

Khoshnood said parents were being told that the lockdown would end at 5 pm. He said he was extremely worried when he first heard about the attack.

"It's hard. Especially after the shooting in Arizona," Khoshnood said. "It's just getting too much."

The officer, identified as Jeffrey Stenroos, an eight-year veteran of the LAUSD police force, was listed in fair condition at Northridge Hospital.

Dr. Stephen Jones said that Stenroos was shot above the heart but that his bulletproof vest largely deflected the force of the gunshot.

He said that Stenroos' mood was upbeat and that doctors were making sure the bullet didn't bruise his heart or lungs.

"If it was me, and I had been shot at that range, I would feel like the luckiest man alive," Jones said.

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-- Andrew Blankstein, Richard Winton, Ann M. Simmons, Nate Jackson, Ching-Ching Ni and Kate Linthicum

Interactive map: Shows location of shooting, nearby schools on lockdown and other information related to the shooting outside El Camino Real High School. Credit: Los Angeles Times