When the strongest earthquake to hit Hawaii in 20 years jolted people awake Sunday morning, causing untold damage to roads and buildings, it turned a paradise dream vacation for many into a nightmare.

In Waikiki, worried visitors began lining up to buy food, water and other supplies.

The quake - estimated to be between magnitude 6.5 and 6.6 - hit at 12:07 p.m. St. Louis time, 10 miles north-northwest of Kailua Kona, a town on the west coast of Hawaii Island, also known as the Big Island, said Don Blakeman, a geophysicist at the National Earthquake Information Center.

It sent rocks tumbling onto highways, crashed the ceiling of a hospital and caused untold damage to buildings and bridges. Aftershocks - one as strong as magnitude 5.8 - continued all day. Hotels reported some minor injuries, but Gov. Linda Lingle said there were no fatalities.

Officials said there was no danger of a tsunami.

Residents had no easier of a time than tourists coping with the quake.

"I was pretty scared," said Anne LaVasseur, who was on the second floor of a two-story, wood-framed house when the temblor struck.

Big Island Mayor Harry Kim estimated that as many as 3,000 people were being evacuated from three hotels on the island. Brad Kurokawa, Hawaii County deputy planning director, confirmed the hotels were damaged but could not say how many people had left. They were being taken to a gymnasium until alternate accommodations could be found, he said.

Many with vacation plans found themselves bogged down in flight delays. Federal Aviation Administration spokesman Les Dorr said that planes were arriving at Honolulu International Airport but that there were few departures.

Earthquakes of magnitudes in the 6 to 7 range are rare in the region, which more commonly experiences temblors in the magnitude 3 and 4 range, caused by volcanic activity.The last Hawaiian earthquake this strong struck more than 20 years ago. The magnitude 6.7 earthquake caused heavy property damage on Hawaii Island and collapsed trails into a volcano in Hawaiian Volcanoes National Park on Nov. 16, 1983.