Revisiting the Earthquake and The Damage It Caused

The damage the 7.2-magnitude Seattle Fault earthquake caused to the Greater King County area ten years ago was immense. Although, the whole county was severely impacted, Seattle’s critical infrastructure was heavily damaged because of its close proximity to the fault. Many utility services such as water, electricity and sewage were interrupted throughout the county. A sufficient amount of transportation infrastructure was also damaged and rendered unusable after the quake.

This story is a work of fiction, including all names and quotes, written by WWU DRR students for public education purposes. Site design by Dr. Scott Miles.

The biggest issue King County faced was liquefaction. This was the main cause of damage to water, wastewater, and electricity infrastructure systems. The earthquake approximately ruptured 200 water supply lines, cracked 100 wastewater lines, and impacted 20 power facilities. This rendered major services to King County unusable.

An unsafe condition that many King County residents lived with prior to the earthquake was the old concrete wastewater lines and non-flexible water pipes. Many systems in King County were built this way and they were highly susceptible to cracking when the ground began to shake and liquefy. The soil types that many Seattle and King County developments are built on, allowed peak ground acceleration to move easily through the land. This broke and disrupted many of the lines that were underground. Following the quake, some communities relied on water that was trucked in and had to use porta potties.

Immediately following the first wave of shaking, Seattle resident Rebecca Morgan walked around her neighborhood to assess the damage.

Rebecca said, “Down the road on the next block I could see several water lines had been ruptured. The water was shooting out of various hydrants, which caused a lot of standing water on the roads in my neighborhood.”

Rebecca went on to say that from the damage she witnessed in her neighborhood, she thought Seattle and King County were likely to be just as bad or even worse. She knew that repairing and replacing the water services was going to be no easy task and more time intensive then she originally had thought.

Sarah Brown, a Sammamish resident, was worried about the pollution that wastewater lines were generating.

“I noticed there was a significant amount of brown water coming from the side of the road that was being carried into the stream behind my house that leads to Lake Sammamish,” Brown said.

This was not the only pollution that residents of King County were concerned with. Many citizens were concerned about the toxic Duwamish River and the liquefaction that occurred around it. Many were worried how the toxic chemicals were further impacted the area and how it would affect the cleanup process.

Industrial worker and nearby resident Ian Brodie was one of the many residents to voice their concerns about the site after the earthquake.

Brodie explained, “The industrial history of the area has degraded the local ecosystem with toxic chemicals and the liquefaction has spread those around. The contaminated soils penetrated our cracked water supply lines and made it where we couldn’t drink the water for a while.”

Some 300 transportation systems were also affected from the earthquake and subsequent liquefaction. These were some of the most vulnerable infrastructures in the King County region. Around ten percent of all King County bridges were damaged. Approximately 70 bridges sustained complete damaged. Many of the other bridges that did survive had to be inspected before they were deemed safe to use.

The built environment was really no match for the powers of the natural environment that were proven by the earthquake. The roads, bridges, overpasses and ports  all sustained damage. Some won’t be able to be fixed. First off all the previous matters stated earlier from the utilities section adversely affected transportation as well. A lot of those major water, gas and wastewater lines run under and follow the roadway system. So when the pipes ruptured, there was significant damage to the roadways too. One issue that caused a lot of destruction was the fact that a lot of major roadways and transportation were built on liquefiable land. The Port of Seattle was violently rattled so much that large chunks of port land were cascading into the ocean. With the ground being so unstable, large soil shifts continued to break the seawall down further.

Following the earthquake, structural engineer Ray Edwards analyzed and reported on all the bridges that were damaged from the earthquake.

He described that, “Within days after the earthquake, it was mine and my colleagues job to inspect all the major bridges and deem whether they were safe to use or not. Many of the major bridges that had received seismic upgrades fared well but many of the neglected bridges didn’t.”

Emergency response worker Taylor Reynolds explained that the impassable bridges and roadways made response difficult and that if left many citizens trapped in the downtown areas.

“Without the infrastructure to move around and be mobile, our work became a lot harder and more complicated. An even bigger problem was getting the necessary survival resources to the people who were trapped inside those areas that were inaccessible by automobiles,” said Reynolds.

The most shocking event that hit us all hard was seeing the Alaskan Way Viaduct. The Viaduct though very unsafe was a key component to the downtown and the ambiance of Seattle’s waterfront. For many though the viaduct was one of the hardest scenes to erase from their minds.

“Luckily I was on the top portion of the viaduct,” Commuter and resident of North Bend John Davis expressed. “I felt the ground give out from underneath me and suddenly I was free falling I heard a huge crack and simultaneously as I started feeling the free falling motion. I am just lucky that I wasn’t on the bottom story of the viaduct.”

The viaduct collapse was reminiscent of the Loma Prieta quake that occurred in 1989 in Northern California. Many buildings had damage, and many fires were started from ruptured lines. But the most impactful moment came when the quake caused the Cypress Viaduct in West Oakland to collapse. A 2 kilometer section of the viaduct came down upon the first layer, resulting in 42 fatalities. Cars on the top layer were tossed around violently and some were flipped sideways resulting in further injuries.

The Cypress Viaduct collapse in 1989.

The Cypress Viaduct collapse in 1989.

Some sections of the bridge created a 4 foot gap from which some people were spared being crushed. However they were stuck inside their crushed cars for many hours while emergency responders tried to get to them. While both the Loma Prieta quake and the one in Seattle occurred at the same time, the California quake had far less fatalities. One of the reasons credited for this was that Game 3 of the 1989 Baseball World Series had just started between the San Francisco Giants and the Oakland Athletics. Because both teams playing were local to the California area, people had already traveled to the game or back home to watch it. This meant that the usually busy viaduct and other freeways were much clearer, resulting in far less fatalities.

Lucky is the best way to describe to John’s experience with the earthquake. But there were many others weren’t as fortunate. When the earthquake hit the timing was just right. When the shaking began it was 5:30 pm. A lot of people were going home at the time, usually taking the viaduct to access the freeways

First responder Nanette Rutherford was the first at the scene of the viaduct. She begins to explain the situation as it unfolded.

“The hardest part had been knowing that there were people in the lower section of the viaduct that were being smashed by the top section falling onto it. Some of the sections of the viaduct even came down to the street level, completely collapsing all the way down. It was a very frightening site to see, but as a first responder you have to get use to those sites” Rutherford explained.