The earthquake (search) was powerful enough to sway skyscrapers 185 miles away in Tokyo (search). And with an estimated magnitude of 7.2, it had the potential to cause catastrophic damage. But this time, Japan got lucky.

No one died in the quake that rocked a wide swath of northern Japan on Tuesday. The scene of the worst damage was an indoor pool where part of the roof caved in, injuring a couple dozen swimmers, many of them young children.

Still, the jolt underscored the fragility of the lifelines of even the most modern, quake-resistant cities. It forced highways and railroads to close, leaving tens of thousands of people stranded, and 17,000 households lost electricity. And with Tokyo overdue for a major quake of its own, it was a psychological jolt for many.

"I was stuck in a stopped train for three hours, and then had to walk about a mile along the tracks to get here," said Shigenori Torihata as he waited for a friend at Sendai's main train station. "I was supposed to go home to Tokyo. Now I'm stuck in a hotel."

The visible damage from the quake was surprisingly light. Few houses were destroyed, and by nightfall the city of Sendai (search) had returned to its normal routine. The streets were crowded with cars, and the malls with shoppers.

Sixty-two people were reported hurt, the worst injuries being broken bones. Most were hit by falling debris, police said.

Damage was minimized because the quake was centered about 50 miles offshore and 12 miles under the seabed. In sharp contrast, a 7.3-magnitude quake centered directly under the city of Kobe killed 6,400 people in 1995.

Though earthquake-resistant construction standards have undoubtedly mitigated the impact of quakes like Tuesday's — older homes are generally far more vulnerable than newer ones — the fragile nature of city lifelines continues to be a major problem.

Sendai's airport quickly returned to a normal schedule, but the city had been largely isolated for several hours, with all major roads and train lines shut down. Electricity was cut off for thousands of households.

"The quake was scary, but the worst part was not being able to get a train home from work afterward," said Natsumi Okumura, a 24-year-old waitress.

The quake hit about 11:46 a.m., the Meteorological Agency said. Two small tsunamis followed, but caused no significant damage.

The temblor was followed by at least four aftershocks. More jolts of up to magnitude 6 could follow, the agency warned.

"We were lucky this time," said office worker Mari Abe, 36. "But there will be another one. It may be years away, but there's always the fear of the next big one."

The U.S. Geological Survey (search) and Japan's Meteorological Agency both measured the quake at a magnitude of 7.2.

Japan sits at the juncture of four tectonic plates — or moving slabs of the earth's outer crust — and is one of the world's most quake-prone regions.

There have been several recent strong quakes in Japan. The biggest, at magnitude 6.0, shook the Tokyo area on July 23, injuring more than two dozen people and suspending flights and trains for hours.

A magnitude 5 quake can damage homes and other buildings if it is centered in a heavily populated area.

The Dec. 26 Indian Ocean earthquake (search) with a magnitude estimated at 9.1 to 9.3 and the tsunami it triggered killed more than 176,000 people in 11 countries, and left half a million homeless in Indonesia alone.