SENDAI, JAPAN—The hangars are flooded with seawater. Under the water, hundreds of tons of muck washed in by the tsunami cover the floor. All the equipment kept at ground level—which, at aircraft maintenance, is just about all of it—is ruined, some of it swept away. The customers' aircraft are floating in the hangars and, with one remarkable exception, all wrecked. The buildings have just been thrown about by one of the most powerful earthquakes in recent history. The runway is submerged and, for all anyone knows, may have been smashed by the earthquake. There is no power. All employees are marooned on top of the administration block, surrounded by water, lucky to be alive.

From that lamentable scene on March 11, 2011, the Sendai Maintenance Center of Japanese aerospace group Jamco is nearing full recovery. When Aviation Week visited earlier this year, its hangars were as full of aircraft as they had been on that terrible day when almost 16,000 people died, including more than 1,000 in the airport district—but not one from Jamco Sendai.

How It Happened

After the earthquake struck at 2:46 p.m. the staff, following emergency procedures, assembled in the car park of the facility, which is 1 km (1,100 yd.) from the coast. The public phone system was down and, without power, they had no access to television, so they knew nothing of the tsunami. Crucially, general manager Noriyoshi Isogami was at Jamco's head office in Tokyo, and he had a working television. Using the company's internal communications system, which has a battery backup power supply, he called Yukio Ida, deputy general manager of the facility, telling him of the pictures of the gigantic wave and urging him to evacuate. That would mean telling everyone to get into their cars and drive inland.

Ida says he looked at the road. It was jammed with the cars of people who had also somehow heard or guessed that a tsunami was coming. He wondered whether they could get inland far enough and fast enough.

Isogami held his phone against the television so Ida could hear the emergency broadcast warning that the tsunami was 10 meters (33 ft.) high. “How high do you think our administration building is?” Ida asked. About 15 meters. Yet it hardly seemed safe to enter a 40-year-old building that had just been shaken by an earthquake. “I thought about the people who had died when buildings had collapsed in the [recent] Christchurch earthquake in New Zealand,” says Ida, reliving the day. Looking again at the jammed road, he made his decision: everyone to the roof of the administration block.

Jamco had 144 employees and 10 customer representatives on site that day, and all stood on top of the building as the tsunami smashed ashore and flooded the airport, sweeping along cars, boats, buildings and aircraft—and people calling for help. Also on the roof were 27 students from an aviation college next door whom Jamco's people had beckoned upstairs. As the tsunami roared across the shore at 3:34 p.m., Jamco's people thought they were finished: The foam of the wave stood twice the height of the trees near the shoreline. But by the time it had crossed a canal and invaded the airport, it was down to 2.6 meters. The office block held.

Some people from the airport region who died were drowned in their cars as they tried to flee. But many others miscalculated by staying.