April Fools' Day has never been the same for the Powlison family of Lanikai, who witnessed the devastation of the 1946 tsunami from their home high above the sea on a promontory that overlooks the Mokulua Islands and Kailua Bay.

It's also the day the federal, state and county governments begin Tsunami Awareness Month, taking the message of preparedness to residents.

On April 1, 1946 a major earthquake in the Alaskan Aleutian Islands generated a huge tsunami that traveled across the Pacific in 4.5 hours to wipe out the waterfront in Hilo, hitting it with waves as high as 39 feet.

Hilo was hit the hardest and is remembered as the symbol of the devastation. But other areas were hit by the tsunami, too, and for those who were there, the memories live on.

In Lanikai, the Powlison family watched in shock as that tsunami generated nine waves that pummeled Kailua Bay and Lanikai Beach, said Cosette Harms, 65. Harms said she was too young to remember the tsunami, but every April Fools' Day the family talks about the event and relives the experience.

Her mother, Peggy Powlison, kept newspaper stories of the costly destruction. About 159 people died and there was an estimated $26 million in damage statewide.

"We watched a piano float by, a huge rowboat was deposited into somebody's living room, furniture, everything was washing around in the bay after the waves were pau," Harms said.

It was trash pickup day, so all the neighborhood trash was sloshing around in yards, beaches and the ocean, she said.

A Lanikai home and a huge coral head were tossed on Mokulua Drive, the street running parallel to the beach homes. "(The coral head) was so big they had to use dynamite to break it apart," Harms said.

Her father tried to call the only two radio stations to warn them when the family first noticed the water receding, but both stations thought it was an April Fools' joke, she said.

So did Earl Kaina's mother. He lives close to the water and it washed across the marble game he was playing in his Lanikai driveway that day.

But he convinced his mother and aunt to come outside. They ran to the beach, Kaina said.

"That's probably the worst thing you could do," he added. His mother recognized the danger and went to warn the neighbors.

Their beachfront home sustained most of the damage to windows and doors, he said.

"Those people were starting to come out of their homes not knowing what happened," Kaina said.

Kaina and his mother will be part of the awareness program "Tsunami Talk Story" at 10 a.m. today at Holy Trinity Catholic School, 5919 Kalaniana'ole Highway.

In Hilo, the exhibit "Wave Machine: Energy of Moving Water" opens today at the Pacific Tsunami Museum, 130 Kamehameha Ave.

When a tsunami is generated in Alaska, the state has time to warn residents, said Delores Clark of the National Oceanic and Atmospheric Administration, a sponsor for Tsunami Awareness Month.

But locally generated tsunami may strike within minutes and maybe seconds after a quake. Clark said there are three warning signs that should send people to higher ground: