A tsunami spawned by an earthquake in Canada sent waves and fear to Hawaii, thousands of miles away, where some residents scrambled to higher land and prepared for a fierce impact.
But by 1 a.m. in Hawaii (7 a.m. ET), a tsunami warning for Hawaii was canceled, and a tsunami advisory was put in its place. An advisory indicates that strong currents or waves that are dangerous to those in or very near the water are expected, but significant inundation is not.
Honolulu Mayor Peter Carlisle said people who had evacuated can return to their homes.
Earlier, local television showed images of bumper-to-bumper traffic on roads leading from the coast to higher ground. About 80,000 people live in evacuation zones on the island of Oahu, where Honolulu is located.
The first waves to hit Honolulu didn't seem much stronger than usual. But scientists warned people not to be fooled by the initial waves, which often aren't the biggest.
"It's not just one wave, it's a succession of waves," Gerard Fryer, senior geophysicist at the Pacific Tsunami Warning Center, told reporters. He said the tsunami could last for hours.
Hawaii State Civil Defense said Wailoa Harbor, on the Big Island, at one point reported a series of 4-foot waves every six minutes.
Even a 3-foot wave could flood several blocks from the shore, Fryer said.
"A 3-foot wave coming into a narrow channel can rise up into a vertical wall, and that will knock you down and beat you up and maybe drown you," he said.
But he noted that the tsunami will not be as significant as the devastating quake and tsunami that killed thousands in Japan in March 2011.
The tsunami warning had come at an unfortunate time -- when thousands of revelers packed streets in Honolulu late Saturday for the annual Hallowbaloo festival.
Many fled amid the warnings.
"You can't really tell which wave is going to be packing the most punch, and sometimes it's the second, third, or even the last one," Carlisle said, while the tsunami warning was in effect. "So it's sort of a train wreck coming through, slowly but surely, and you have to make sure that you have a very good idea that the worst is by you before you start sending people back into the areas that could be affected."
Even Hawaiians accustomed to tsunami warnings spared no effort in bracing for the worst.
Honolulu resident Victoria Shioi filled her bathtub with water, set her refrigerator to the coldest setting and gathered candles in case of water or power outages.
"Also backed up my computer and put the external (hard drive) in the waterproof safe," Shioi said.
The tsunami was spawned by a sizable earthquake in western British Columbia, prompting a local tsunami warning.
"A (magnitude) 7.7 is a big, hefty earthquake -- not something you can ignore," Fryer said. "It definitely would have done some damage if it had been under a city."
Instead, the quake struck about 139 kilometers (86 miles) south of Masset on British Columbia's Queen Charlotte Islands. No major damage was reported.
The Alaska Tsunami Warning Center issued a warning for western British Columbia from Vancouver to the southern panhandle of Alaska.
Canadians as far away as Prince Rupert, on mainland British Columbia, felt the quake.
Tanya Simonds said she felt as if her house was "sliding back and forth on mud," but didn't see any damage from the tremor.
Shawn Martin was at a movie theater when the quake struck.
"It just felt like the seats were moving. It felt like someone was kicking your seat," he said.
Martin said more than hundred cars headed toward a popular intersection in the city known for its higher ground.
Thousands of miles across the Pacific, residents in Hawaii did the same.
"The rest of the Pacific does not have to worry, but Hawaii does," Fryer said.
According to the United States Geological Survey, the quake in Masset occurred as a result of oblique-thrust faulting near the plate boundary between the Pacific and North America plates.
This region of the Pacific: North America plate boundary has hosted seven earthquakes of magnitude 6 or greater over the past 40 years.