COOS BAY — Several thousand Oregon Coast residents on alert after last year’s devastating earthquake in Japan took part in their first tsunami evacuation drill Thursday, stopping what they were doing and walking uphill to assembly points where volunteers handed out bottles of water and grab-bags of essentials.

Unlike a real tsunami, there were no sirens and no tremors from a massive offshore earthquake in the towns of Coos Bay, North Bend and Charleston.

But after weeks of door-to-door canvassing, flashing roadside signs and community meetings sponsored by the Oregon Department of Geology and Mineral Industries with help from a federal grant, people knew what was coming at 2 p.m. when an announcement came over a local radio station. They also knew that in the event of an actual massive earthquake generating a surge from the Pacific Ocean, they would have had about 20 minutes to get to higher ground before tsunami waves arrived.

At Blossom Gulch Elementary School, the kids in Carli Ainsworth’s kindergarten class watched the clock, calling out the minutes until principal Jodi O’Mara announced that the drill was on. They got up from the rug where they were holding show and tell and crawled under the brightly colored tables.

“It’s not a real one,” one boy assured a friend. When the announcement came it was time to evacuate, another little boy said solemnly, “Phew, that was close.” Then the 400 kids, teachers and staff walked uphill on sidewalks past bungalows, rhododendrons in bloom and flashing fire department SUV lights to a high school football field.

Along the way, Tom Paris called out from behind his picket fence that they were doing great, and only 15 minutes had passed. Since his home was at 50 feet elevation, he was not taking part, but applauded the effort. “It needs to be done after what has gone on around the world,” said Paris, 79. “Hopefully, I’m too old to see one. I’ve got my boat tied up out back if it comes to that.”

When the tsunami from the Japan earthquake reached the U.S. last year, coastal residents had hours to prepare, and severe damage was limited to harbors such as Crescent City, Calif. 25-year-old Dustin Weber, son of Bend resident Jon Weber, died after being swept away from a beach near the mouth of the Klamath River.

The much bigger threat here would be a potential megaquake from the Cascadia Subduction Zone, where two plates of the Earth’s crust butt together miles off the coast. When they slip, they could send a 40-foot surge of water moving at the speed of a jetliner into the Oregon coast, Northern California and Washington.