It was an ominous way to start the school year: Flashing lights on police cars and ambulances parked outside the high school, startled children trying to get out, panicked parents trying to get closer.

The crisis drill scheduled yesterday at Chesapeake High School, five days before classes were to begin in Anne Arundel County, may have cast an unusual shadow on back-to-school season. But it reflects the new concerns with safety and preparedness among school administrators in the post-Columbine era.

"This is something we need to do," said Huntley J. Cross, the county school system's special assistant for student discipline, "but in my wildest imagination I never [before] would have perceived that we'd have to do this."

Security is just one issue preoccupying Arundel officials as they prepare to welcome an estimated 74,900 students--about 500 more than last year--for the school year.

As they scramble to fill their final slots for this fall, officials are looking ahead for ways to battle a worsening teacher shortage in coming years. Meanwhile, a booming economy has made it harder to fill many support positions: This month, school officials are running last advertisements in churches and movie theaters begging able bodies to come to work as cafeteria employees.

School and county officials also are trying to get on track with an ambitious construction plan to chip away at a multimillion dollar backlog of repairs in aging school buildings. And debate likely will reopen this year over whether the appointed school board--so often at odds with the elected county executive and County Council--should become an elected board.

Although state lawmakers have been cool to a proposed change in the past, last week's resolution by the County Council in favor of an elected board likely will lend the issue momentum.

But the first order of business this fall is security. The school shootings in Littleton, Colo., and other seemingly safe suburbs last spring sent shock waves through the education community.

While many districts have been rushing to establish crisis-reaction plans and clamp down on discipline, Arundel officials note--without cheer--that they were way ahead of the crowd.

Starting in spring 1997, a series of phony bomb threats disrupted area schools on an almost daily basis and forced school and law enforcement officials to grapple with the threat of violence early on.

"We've had almost an advance, if you will," said county police spokesman Lt. Jeffrey A. Kelly. "We put a lot of changes in place because of all the bomb threats. We became very experienced in handling those things."

School, police and fire officials started meeting monthly, along with county prosecutors, to compare notes on student violence and to cooperate on strategies. They designed a systemwide crisis-reaction plan, as well as smaller plans for each school. And they started aggressively pursuing the student pranksters who delivered the phony threats, expelling them and fining their parents.

While Anne Arundel has not adopted the security cameras and metal detectors now used by many other school systems, it has followed the trend of stricter punishment and a zero-tolerance stance toward students who are found with a weapon or who threaten others with violence.

"Three or four years ago, I doubt we would have expelled them," Cross said. Typically, those students might have drawn warnings and temporary suspensions. "But now, we've moved that behavior up a notch in the progression of discipline."

Still, the school shootings led Arundel officials to believe they needed to do more. "Last year in looking at some of the [shooting] events, it's not that the police and schools were at odds with each other, but that the police had not been in the schools other than for routine things," Cross said. The simulation at Chesapeake High School was designed to give police and rescue workers some practical training within the confines of a typical school.

But the training also was designed to help school officials, who Cross said would bear much of the responsibility for handling the chaos that breaks out at a crisis scene.

"Just the logistics of what you as a separate school would do to accommodate the press, how do you accommodate the parents, how do you get kids home," he said. "It's like somebody who's had three hours of first aid, and suddenly you're in a train crash."