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It’s been 70 years since the earth shook for an entire minute. Are we due for a repeat?

Karen Carlbom Strand was 9 when her raisins danced a jig on her school desk.

She was laughing at the oddity while her teacher panicked, kicked off her high heels and yelled for students at Jefferson Elementary School to line up by the blackboard.

As the ground beneath Tacoma shook, children walked down rickety wooden stairs and outside into the schoolyard.

“It was really hard to hang on because everything was moving so much,” Strand, now 79, recalled.

The earth rocked for an entire minute, starting at 11:55 a.m. on April 13, 1949.

A second wave came 18 seconds later, felt across more than 150,000 square miles from British Columbia to Salem, Oregon, and over to Idaho and Montana.

Even though the needle was knocked off the seismograph at the University of Washington, it recorded vibrations for 21 minutes.

Four people in Washington state died of heart attacks brought on by the earthquake. Four others, including an 11-year-old Tacoma boy, were killed by falling rubble.

It was the largest earthquake to hit the state since 1872. Officials say the next big one could hit in the next 50 years.

“Even the deep-fault earthquakes are doing significant damage, and these are the smallest of earthquakes,” said Maximilian Dixon, hazards and outreach program supervisor for the Washington State Emergency Management Division. “When we get a big one, woooo, that’s going to be bad.”

‘EXTENSIVE DAMAGE’

Scientists initially ruled the 1949 quake a 7.1 magnitude. About a decade ago, earthquake experts re-analyzed the data from April 13, 1949, and decided it was closer to a 6.8 temblor.

“It’s fair to say that of the three significant earthquakes in this area, it did the most extensive damage,” said Harold Tobin, director of the Pacific Northwest Seismic Network.

Statewide, damage estimates totaled $25 million.

Eight buildings at the State Capitol in Olympia needed repairs. More than 30 school buildings used by 10,000 students were rendered unsafe. At least 10,000 chimneys fell into yards.

Puyallup City Hall and Puyallup High School had to temporarily close. Two houses on Fox Island were found floating in Puget Sound. Water mains burst, railroad service had to be suspended, rubble fell on parked cars, giant cracks split open city streets and business windows shattered.

A large sandy spit jutting north of Olympia disappeared.

At the construction site where the new Tacoma Narrows bridge was going up, a 23-ton block of steel tumbled 507 feet from a tower into the water below.

Three days after the quake, a 200-foot section of a hill crumbled near Salmon Beach and caused a small tsunami.

In Puyallup, geysers broke through the surface near East 23rd and G streets through a 60-foot jagged crack and shot water and fine white sand from the old Puyallup River bed five feet into the air.

As people struggled to clean up after the earthquake, Tacoma mourned 11-year-old Marvin Klegman.

A crossing guard at Lowell Elementary School, officials knew Klegman died after being struck by falling bricks.

It would be decades before Kelcy Allen, a kindergartner at the time of the quake, came forward to tell how Klegman died while leading him to safety out of a basement at Lowell.

When bricks started raining down around them, Klegman threw himself on top of the younger boy.

Allen said he’s lived a full life and never stops thinking about the little boy who protected him.

“I have used every bit of my time,” Allen told The News Tribune in 2015. “I figured I better not waste it, because some little boy gave up his existence for me.”

A bronze statue went up outside Lowell in 2003 showing two boys holding hands and running for their lives with rubble on the ground around them.

ANOTHER POSSIBLE IN 2030?

There have been two major earthquakes in the region since 1949, but neither matched its geological upheaval.

One came the morning of April 29, 1965. It rattled the ground for 45 seconds, killing seven and causing $12.5 million in damages.

That temblor was a 6.7 magnitude.

After that was the Nisqually, a 6.8 quake which struck Feb. 28, 2001 and shook the earth for 40 seconds. It injured about 400 people, but there were no fatalities. Damages surpassed $2 billion.

Although the magnitudes of the 1949 and 2001 earthquakes were similar, the Nisqually was only one-third as strong as the 1949 quake in terms of energy released, according to the Pacific Northwest Geodetic Array at Central Washington University.

“For their strength, they actually were less damaging than you might expect,” Tobin said.

That’s because all three of the major temblors were deep, about 40 to 70 miles below the surface, and the depth helped to buffer some of their force.

Seattle ranks seventh among cities nationwide at risk of earthquake damage, according to a study by the Federal Emergency Management Agency. Tacoma ranks 22nd.

Deep earthquakes like in 1949, 1965 and 2001 typically occur every 20 to 50 years.

Those quakes were triggered by the Juan de Fuca plate being pushed beneath the North American plate. Based on historical patterns, another is possible by 2030.

Most likely to wreak havoc in the Pacific Northwest is a crustal earthquake, officials say.

That’s because several big cities sit on top of or near shallow crustal faults like the Seattle Fault, which runs beneath CenturyLink Field, west to Bainbridge Island to Hood Canal and east past Issaquah roughly following Interstate 90.

The Seattle Fault last let go about 1,100 years ago.

There’s an 84 percent chance Western Washington is hit by a deep earthquake within the next 50 years, and a 15 percent chance of a crustal quake, Dixon said.

The most powerful and dangerous is a subduction zone quake, which can range in magnitude from 8.0 to 9.0 and happen roughly 20 miles below the surface.

Those can cause prolonged shaking, tsunamis and large aftershocks.

A subduction zone quake hasn’t struck the Cascadia fault offshore the Pacific Northwest since January 1700. Scientists believe the quake was a 9.0, triggering a tsunami within minutes.

“When we think about the potential for the big one, the highest probability is a quake like in 1949, 1965 and 2001,” Tobin said. “That’s the most activity we’re seeing seismically.”

Types of earthquakes in Washington state:

Deep — The Juan de Fuca plate is being forced beneath North America and into the Earth’s mantle. The plate’s crust is made of basalt and marine sediments and when the slab bends and breaks, it causes quakes every 20 to 50 years.

Crustal — These occur in the North American plate at shallow depths of 20 miles or less.

Subduction zone — Strain is building where the oceanic Juan de Fuca and continental North American plates are locked and will result in major future quakes. Usually occur every 500 to 600 years.

Volcanic — Triggered by changes to magma inside of and underneath volcanoes. When magma levels change, surrounding rock shifts and rattles the earth.

Get prepared

If a major earthquake hits the Pacific Northwest, emergency management officials estimate it could be at least two weeks before some areas receive assistance.

People should create emergency kits with enough supplies of food, water and medication to last this long.

Emergency kits should be portable and can be kept at home, work and in the car. Suggested contents include:

▪ Flashlight and radio with extra batteries.

▪ Water and non-perishable food.

▪ First aid kit.

▪ Copies of driver’s licenses, insurance information and out-of-area contacts stored in watertight bag.

▪ Spare home and car keys.

▪ Change of clothes.

▪ Blankets or sleeping bags.

▪ Diapers or feminine hygiene products

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