A tsunami triggered by a 7.7 magnitude earthquake thousands of miles away in Canada has hit the island chain of Hawaii, without causing major damage.
Emergency sirens sounded to alert residents late on Saturday, and people were ordered out of of low-lying areas.
The first waves were reported to be up to 2.5ft (76cm) in one area, but were generally smaller than expected.
Hours later, the tsunami warning was downgraded and the state governor said Hawaii could count its blessings.
Wave heights of three to six feet had been predicted in some areas.
The quake struck 125 miles (200km) south-west of the Canadian town of Prince Rupert at a depth of 11 miles (18km), said the US Geological Survey.
While the Pacific Tsunami Warning Center did not initially expect a threat beyond the immediate area, it later warned that a tsunami had been generated "that could cause damage along the coastline of all islands in the state of Hawaii."
The centre called for urgent action to protect lives and property. People living in areas considered to be at risk were urged to move to higher ground.
First waves hit the archipelago, made up of hundreds of islands spread over some 1,500 miles, from around 22:30 local (08:30GMT).
A senior scientist at the Pacific Tsunami Warning Centre, Gerard Fryer, told journalists that while the tsunami had arrived as predicted, he had been "expecting it to be a little bigger."
A civil defence source tweeted that Wailoa Harbor on Hawaii island was reporting 4ft waves every six minutes.
The Pacific Tsunami Warning Center said, in an announcement posted at 00:54 local, that the tsunami warning was cancelled.
"Based on all available data, the tsunami threat has decreased and is now at the advisory level and not expected to increase.
"Sea level changes and strong currents may still occur along all coasts that could be a hazard to swimmers and boaters as well as to persons near the shore at beaches and in harbours and marinas. The threat may continue for several hours," it said.
In the wake of the cancellation, police began reopening roads and people in low-lying areas area were being allowed home, local media reported.
"We want to make certain that everybody understands this advisory now. The water is still treacherous; the water is still dangerous but we can go home and, as I say, we can count our blessings here in Hawaii," Governor Neil Abercrombie said.
Earlier, an eyewitness watching the beaches on Kauai island told the BBC that the waves were big and that a "strange mixture of fear and anticipation" reigned.
"A plane with a siren flew over ... and everyone left the beach and coastal buildings. All the boats have been taken out of the water. It's empty down there which is weird. People went buying gas and groceries," Mike Dexter-Smith said.
The quake struck the coast of western Canada at around 03:00 GMT and was followed by a 5.8 magnitude aftershock.
There were no immediate reports of damage on the Canadian coast following the earthquake.
Tsunami alerts that were issued for coastal areas of Alaska and British Columbia were swiftly downgraded.
Urs Thomas, operator of the Golden Spruce hotel in Port Clements, close to the epicentre, said the initial quake lasted about three minutes.
"It was a pretty good shock," he told Associated Press. "I looked at my boat outside. It was rocking. Everything was moving. My truck was moving."
A resident of the mainland town of Prince Rupert, Grainne Barthe, told AP: "Everything was moving. It was crazy. I've felt earthquakes before but this was the biggest. It was nerve-wracking. I thought we should be going under a table."
Following the quake, small waves measuring 69 cm (27 inches) were reported on the north-east tip of Haida Gwai, while parts of the north-east coast of Vancouver Island saw waves up to 55cm high.