A Familiar Plot Line : ‘High Incident’ season finale finds its inspiration in the bank robbery in North Hollywood.

The ABC police drama “High Incident” is filmed in the San Fernando Valley, so when producers decided they wanted to end their season with a bang, they didn’t have to look far for a plot.

Cast and crew are at work in the Valley suburb of Chatsworth this week on a season finale based on the dramatic Feb. 28 North Hollywood bank robbery, which was captured live on television.

“I was driving in to work and my secretary called to tell me about the robbery,” said “High Incident” executive producer Ann Donahue. “When I saw it, it struck me, ‘Oh, my God! That literally looks like one of our episodes!’ ”

Immediately, Donahue had researchers gather newspaper clips from across the nation to get different perspectives on the robbery, which left 10 officers and three civilians wounded and two robbers dead.

Donahue then secluded herself at home for three days and wrote the episode, which will air May 8 and attempt to simulate the spectacular eruption of firepower that draped a shroud of fear over a vast residential area of the eastern San Fernando Valley.

“I don’t think it can possibly be more dramatic than the real thing,” Donahue said. “What we’re trying to do is be as dramatic, and I think we succeeded.”

The script differs slightly from the real crime but includes the same battlelike exchange of gunfire outside a bank as robbers in full body armor spray bullets at outgunned officers.

“Everyone in the country saw it live, so we’re not trying to re-create it,” said director Art Monterastelli, who happened to be in North Hollywood scouting filming locations on the day of the robbery. “We’re just basing the show on it and creating our own human drama.”

The episode--which utilized consultants from the Los Angeles Police Department--advocates better and stronger weapons for the police, Donahue said. In one scene, the town mayor attempts to cover up the disparity in firepower between the criminals and the cops, but an officer insists on bringing it to light.

In the real incident, the weakness of the LAPD’s weaponry was openly addressed by both representatives of the media and the police department. In less than three weeks the Los Angeles Police Commission approved the replacement of standard 9-millimeter service weapons with more-powerful .45-caliber handguns for officers, and high-powered rifles were deemed necessary in the squad cars of patrol supervisors.

But officers in “High Incident,” like members of the LAPD on Feb. 28, possess no such weapons. They are vulnerable, overpowered by the assailants and, in the end, severely wounded.

“It’s great that we’re telling a story and the whole country isn’t going to say, ‘That can’t happen in the suburbs of America,’ ” said “High Incident” star Blair Underwood. “Our best episodes have been ones based on real stories.”

The episode takes place in the parking lot of an empty Chatsworth building, which serves as El Camino City Bank in the fictional suburb of El Camino. Surrounding Valley neighborhoods are used to film scenes in which officers hunt down fleeing robbers.

The episode features officers Mike Rhoades (Underwood) and Jessica Helgado (Lisa Vidal), who are about to end a shift when their patrol car rams head-on into the vehicle driven by a suspected robber in the bank’s parking lot.

A barrage of gunfire breaks out, and eventually two officers are hit. One is left paralyzed, the other in a coma.

Underwood believes this episode could give the show a much-needed ratings boost. “It always runs the risk that you’re cashing in on current events, but I think it’s really going to help the series,” he said.

“High Incident” ranks 104th out of 154 prime-time shows this season, but a spokeswoman for ABC says there’s a strong possibility the series will be picked up for a third season when the network renews contracts in mid-May. Everything is relative when your competition is the huge NBC hit “Friends.”

Normally, it takes eight days to film an episode of the series--which was co-created by Steven Spielberg and is produced by his DreamWorks Television--but this one will span nine days because the plot is more complicated than most. There are also more time-consuming special effects and stunts than in the average “High Incident” episode.

“Because of the intensity, it’s a heavy special-effects-laden show,” producer Jack Clements said. “We had more bullet hits in this show than we’ve done all season.”

For actress Vidal, re-creating the crime was particularly emotional, since she lives in nearby Sherman Oaks and her son’s school is a few blocks from the site of the robbery. During the filming she “felt sick over it,” she said. “It’s pretty deep for me doing this now, and it feels kind of eerie.”

Underwood didn’t have the same visceral reaction to the event; he isn’t a Valley resident and on the day of the crime was so busy with his newborn son he didn’t even watch TV. So to prepare for the show, he viewed a tape of the robbery.

“I couldn’t have been as calm as the real cops,” he said. “I’m glad I’m doing this and not that.”

* “High Incident” airs Thursdays at 8 p.m. on ABC (Channels 7, 3).