Like a scene from the madcap adventures of television's super-agent Maxwell Smart, security doors at Defense Intelligence Agency offices in Arlington locked shut early yesterday morning during a power failure, sealing several analysts in their upper-story roosts.

Fire officials, however, aren't laughing.

Had there been a fire in the 12-story Rosslyn office building known as Pomponio Plaza, they fear workers on four of the top floors would have stood a good chance of being trapped.

"If you were unfortunate enough to get out of an elevator on one of those floors," said Arlington's deputy fire marshal, John Smith, "you would be trapped there.You'd have no way to get to the stairways" and out of the building.

Yesterday's power outage was the second such incident in as many weeks. Both times the building's emergency power system failed to turn on, trappng people in elevators, leaving stairwells without lights and sealing floors eight through 11 from the rest of the building.

The most recent imbroglio comes a week after the Arlington County fire marshal's office cited the building's management for a fire code violation in failing to maintain the back-up power generator.

Government Services Administration officials say they have been aware for two years of a hazard at DIA's secret information processing offices.

"We've never felt (safety) was adequate and neither has Arlington County," said Carol Bowling, GSA assistant buildings manager. "We would like considerably more work to be done than Defense would like to see done."

Bowling described the "fail-lock" security doors as a hazard resulting from a "philosophical conflict" between the GSA and the defense Department. GSA has pushed for safety, while Defense for security.

"When you have such high security requirements," said Buildings Manager Richard Moore, "safety features are sometimes circumvented."

The Pomponio Plaza went black shortly after 7:30 a.m. yesterday, just as DIA's approximately 350 top-floor employes, many of them military brass, were arriving for work.

Security guards, who asked not to be identified, described the ensuing events hour's in some of the windowless intelligence offices as high comedy.

"It was completely dark," said one. "You couldn't see a thing. One lady was yelling, 'I'm scared! I'm scared! I can't find my way out! And at that point, I was just feeling my way around with my hands. I told her, I'm in the same boat as you are! Finally, we touched hands."

Another woman yelled for assistance from a bath room. when a guard eventually found her, she asked him to wait by the door so she could go back and look for her purse.

Others were trapped in elevators. Firemen worked for nearly an hour with a woman wrapped in darkness in a stranded lift. They pried the elevator doors partly open to give her tools and she succeded in tripping a door herself to make an escape.

But some wondered what might have happened had the building been in flames. "It's ridiculous," said one guard. "Because if you're in a lobby and nobody knows you're there, you are going to burn to a crisp."

Moore said GSA and Defense officials plan to meet Wednesday and that the problem "will be resolved."