HONOLULU ? 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, one of the state’s busiest tourism areas, worried visitors began lining up outside darkened convenience stores to buy food, water and other supplies. Managers, fearful of chaos, let tourists in one at a time.

Karie and Bryan Croes waited an hour to buy bottles of water, chips and bread. The newlyweds had never been in an earthquake before.

“It’s quite a honeymoon story,” said Karie, as she and her husband sat in lounge chairs surrounded by grocery bags at ResortQuest Waikiki Beach Hotel.

The quake – estimated to be 6.6 magnitude – hit at 7:07 a.m. local 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, part of the U.S. Geological Survey.

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, and the most serious injury report she had was a broken arm.

Officials said there was no danger of a tsunami, though choppier-than-usual waves were expected in some places. Beaches were devoid of sunbathers and largely deserted, save for a few dozen die-hard surfers in Waikiki.

People wait in line for food at a roadside chicken stand in Kihei, Hawaii, on the island of Maui. An earthquake that struck the big island of Hawaii on Sunday knocked out power on several islands and forced restaurants and other merchants to close.

Residents, who had not experienced such a strong earthquake since a 6.7-magnitude quake caused heavy property damage in 1983 on the Big Island, had no easier of a time coping with the quake than tourists.

“We were rocking and rolling,” said Anne LaVasseur, who was on the second floor of a two-story wood-framed house on the east side of the Big Island when the temblor struck. “I was pretty scared. We were swaying back and forth, like King Kong’s pushing your house back and forth.”

Big Island Mayor Harry Kim estimated 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.

The quake caused widespread power outages, and phone communication was possible but difficult. By midday Sunday, power was restored to Hilo on the Big Island and was starting to be restored to Maui, said Chuck Anthony, a spokesman for the Hawaii National Guard.

Some Honolulu neighborhoods also had power late Sunday afternoon, a spokesman for Hawaiian Electric Co. said.

Officials did not have a firm estimate of how many people were without power.

A FEMA computer simulation of the quake estimated as many as 170 bridges on the Big Island could have suffered damage in the temblor, said Bob Fenton, FEMA director of response for the region. More than 50 federal officials were en route to the Big Island to assess damage and begin recovery work, he said.

A young surfer charges in front of a wave at Maili Beach, Hawaii, on the island of Oahu. Sunday's earthquake did not trigger a tsunami warning, but scientists said wave activity around Hawaii could increase.

On Hawaii Island, there was some damage in Kailua-Kona and a landslide along a major highway, said Gerard Fryer, a geophysicist at the Pacific Tsunami Center. Officials also said there were reports of people trapped in elevators in Oahu.

Many with vacation plans found themselves bogged down in flight delays. Airports were functioning despite the power outages, though travel was difficult and some flights were being canceled, officials said.

Federal Aviation Administration spokesman Les Dorr said planes were arriving at Honolulu International Airport, but there were few departures. Dorr said the Transportation Security Administration security checkpoints were without power, so screeners were screening passengers and baggage manually.

Resorts in Kona were being asked to keep people close to hotels, Kim told television station KITV. Cruise ships were asked to keep tourists on board, and ships that were due to dock with tourists were asked to move on to their next location, he said.

“We are dealing with a lot of scared people,” he said.

Aftershocks could continue for weeks, experts said.

Earthquakes in the 6.0-magnitude range are rare in the region, though they have happened before. The region more commonly sees temblors in the 3- and 4-magnitude range caused by volcanic activity.