Some thought it was the subway or a plane flying overhead. Others thought they felt an explosion, perhaps at some nearby factory. A few dreamed of eternal damnation . . . and a lot of people slept right through it.

An earthquake, minor by official standards, but apparently the largest to center near the New York metropolitan area, shook skyscrapers and rattled nerves from Philadelphia to southern Canada at 6:08 this morning.

It measured 3.8 on the Richter scale, and was felt most strongly near New Rochelle in Westchester County, about 20 miles north of New York City.

Police in New Jersey, New York and Connecticut were flooded with thousands of calls from worried residents, unaccustomed to the kind of tremors that are routine in the western part of the United States.

No injuries or serious property damage were reported.

The quake was felt at Consolidated Edison's Indian Point nuclear power plant near Peekskill. It was an unusual event, the least serious of four emergency classifications, but the plant continued to operate, according to spokesman Martin Gitten.

But for many citizens, the quake was traumatic. "It was like a bomb fell," said Cyna Ben Ari, 38, who was awakened in her split-level house in Paramus, N.J. "It went 'BOOM!' I went crazy. I was clutching my bed. The mirrors were shaking."

In Yonkers, a few miles from the center of the quake, Robert Meaney, 57, a supermarket manager, heard "a tremendous roar, as if a subway train went right under me." He jumped out of bed, rushed into the hall and bumped into his 24-year-old son, Michael, also roused from sleep.

"My son said, 'It felt like an earthquake.' I told him, 'Naw, you're crazy,' " Meaney said.

Minor quakes are common in the Northeast -- a central New Jersey quake registered 3.4 on the Richter scale in October 1981. The strongest recent quake in New York state, in the Adirondack Mountains in 1983, measured 5.2.

The Richter scale measures ground motion as recorded on seismographs. An earthquake of 3.5 on the scale can cause slight damage, while a 5 is considered dangerous and an 8 is a huge quake capable of causing massive damage.

However, many New Yorkers were shocked. "I kept thinking about Mexico City, and the mudslide in Puerto Rico," said Julia Perez, 46, a welfare mother. Perez said her building, a public housing project in Manhattan, "trembled. I couldn't believe it. I thought everything was going to fall down."

This afternoon, along Broadway, the quake was the talk of the town. "It's like, really!" said cab driver Jay Plever, at a Blimpie's. "It's like, amazing! This isn't supposed to happen in Manhattan."

Mattie Gosling, 74, munching a sandwich nearby, shrugged indifferently. "It woke me up," she said. "But I'm from California, so I knew what it was. I turned over and went back to sleep."

Yvonne Humphrey, 27, jumped up and down to recreate the excitement she felt at the tremor. When it happened, "I was just lying down and thinking about how I had to get my life together," she said. "I called my mother and I said, 'It's God!' "

"I think I'm going to spend my whole paycheck today, just in case there's another earthquake," said Maria Capote, 22, a receptionist. "But if there is, when will I get a chance to wear this stuff?"