SEASIDE, Ore. - Tsunami sirens sounded Wednesday afternoon along the Oregon coast, sending residents scrambling for higher ground.

But it was just a drill, and no killer waves were headed for the coast.

The exercise was just the latest event in a series of exercises designed to save lives if a real tsunami bears down on the coastline.

Scientists have long warned that a powerful earthquake off the coast of the Northwest could trigger a tsunami similar in strength to the one that killed well over 100,000 people along coastlines in the Indian Ocean on December 26, 2004.

The multiple active fault lines and shifting tectonic plates under the waters of the Pacific Ocean just off the Oregon and Washington coast have a verified history of violent earthquakes that could cause a powerful tsunami to head for the nearby coastline.

Participation in Wednesday's drill was voluntary, but when warning sirens sounded at about 11 a.m., scores of local residents and hundreds of school children headed uphill to designated safety areas.

For emergency officials, the goal was to see how large groups of people coped with moving a mile in twenty minutes.

Officials encouraged people to walk to safety areas after a real tsunami scare in 2005 resulted in car traffic gridlock that left many stranded in the danger zone.

This time, police diverted vehicle traffic to keep primary streets clear for pedestrians heading to safe areas.

Seaside mayor Don Larson said the main concern for the latest drill was to see if they could evacuate all local school children to the safety area within 20 minutes.

The effort seemed to meet with success as 1,600 kids milled about on higher ground, waiting for the all-clear to sound.

But some residents said they were not able to reach the safe area in the allotted time.

Officials say they will continue to tweak their evacuation plans with more drills in the future.