But in his escape effort, Fasullo had an advantage over the hundreds of others trapped by the fire - he helped design the World Trade Center more than 20 years ago.

So, while a recorded voice in the elevator told them to just be patient, Fasullo and the seven others in the elevator began cutting their way through a wall, using the car keys in their pockets. They hacked away like frantic prisoners pulling a jailbreak.

When the elevator's emergency battery ran out, they used the dim lights from their pagers to guide them through the utter darkness.

Finally, after three hours, Fasullo and the others broke through the elevator shaft into the stall of a 58th-floor restroom.

"I almost put my foot in the toilet bowl," he said yesterday. "But at that point in time, everything in the world looked beautiful, even that bowl."

"Because of our knowlege of the Trade Center - we helped build the thing - we knew what we had to cut through," said Fasullo, 62, director of engineering for the Port Authority of New York and New Jersey, which owns the Trade Center.

Fasullo and four other Port Authority engineers had just left their office on the 72d floor of One World Trade Center on Friday when the elevator shuddered to a halt. They tripped the alarm button.

"A voice came on and said, 'We've recorded your message and be patient,' " said Fasullo, a slender man of medium height and thinning hair. "So we waited and waited. Time went by, and then all of a sudden some smoke started coming into the car.

"Then we started thinking maybe it was something bigger than the normal power outage, which happens all the time."

As the smoke thickened, the engineers began thinking about their options. They knew they were on an express elevator - which meant that below the 62d floor, there are no doors leading from the shaft to the surrounding floors. So they could not just pry open the doors and hope to slip out.

"We were yelling and screaming," he said, his voice hoarse from smoke. "We didn't hear a peep. Nothing."

So they decided to take action. First they pulled a panel off the side of the car. They met a steel wall. Then they pulled the ceiling down, but found no door to escape outside.

"Then we forced the elevator doors open," he said. "Luckily, they opened. That gave us the face of the shaft, a fire-rated wall."

The wall, he knew, was two 1-inch-thick pieces of sheetrock with metal studs every 12 inches. They kicked the wall, but it was too firm to break.

So they cut at the wall with their keys, slowly creating a slot in the plasterboard. Fasullo pressed so hard he rubbed his knuckles raw and bent the key to his Honda. His fingers yesterday were covered with bandages.

"The wall was hard as a rock," he said. It took an hour to cut through the first 1-inch-thick piece.

"We had smoke, we were coughing, our eyes were teary, and then the lights went out," he said.

Three of the engineers discovered that the pagers on their belts gave off a small amount of light.

"You put the light right on the wall to see the hole," said Fasullo. "Some of us were holding open the door, some were holding the light to the wall, and some were scraping like hell, coughing. It was really serious. The smoke was so acrid."

"There was a period with the smoke, where we were almost to the point of collapse. My body was shaking. I never experienced this before. I was sitting on the floor for a while and my body was shaking."

Eventually, one of the engineers pried the button panel off the wall. The metal panel proved to be a better tool to cut through the wall than car keys.

Soon, they broke into the plenum - the 2-inch-wide space between the interior and exerior walls, separated by the studs.

Fresh air rushed in.

"Oh, the elation," he said. "My knowledge of fires is that the smoke is what kills most people, not the fire. So once we got fresh air, I knew our chance of continuing was much improved."

Still, nobody came to the rescue. So the engineers cut through the last wall, not knowing what floor they were on or what lay ahead. When they heard tiles crashing to the floor, they knew they were at a restroom.

They enlarged the hole and began squeezing themselves into the restroom.