Uncovering The Truth Behind Washington’s Mysterious Sinkholes

What are the top 10 states with sinkholes? Florida, Texas, Alabama, Missouri, Kentucky, Tennessee, and Pennsylvania. All are prone to sinkholes due to the composition of the bedrock.

Some may associate sinkholes with the southern United States, particularly Florida.

Sinkholes can and will occur anywhere, like here in Washington. Washington isn’t typically known for being a hotbed of sinkholes, but in recent years, the number of sinkholes has increased. 

Seattle has seen its share of man-made sinkholes, caused by water main breaks or the failure of old pipes, which act like caves or voids beneath the surface.

The rash of Seattle sinkholes

• A sinkhole in 2011 was three stories deep in West Seattle.

• Another sinkhole on the Seattle waterfront that trapped a 60-year-old man for about an hour in 2009. 
• The year 2007 saw a sinkhole near the Seattle University Bridge that swallowed two cars in 2007.  
• Ask your grandparents about the "great Ravenna sinkhole" of 1957 - 50 feet deep, 120 feet wide, and more than 200 feet long! 

• Back in 2013, when the Seattle Highway 99 tunnel was being built, Bertha, the drill, caused a massive sinkhole measuring 15 feet long, 20 feet wide, and 7 feet deep.

• In 2016, Seattle experienced several sinkholes, including one in the middle of the road in Rainier Valley and another that opened up between two homes in Queen Anne.  

Washington Sinkholes in the last five years

• A massive sinkhole opened in Winlock, located in Lewis County, southwest of Washington, in August 2021.

• WSDOT closed I-82 after a large sinkhole was discovered in February 2024.  The sinkhole was spotted near milepost 44, with feet of dirt suddenly missing from under the road.

• A large sinkhole was discovered in August of 2024 in Grandview.

• Fast forward to April 2025, when heavy rains recently caused a sinkhole on the Cowlitz County West Side Highway, along State Route 411, near Castle Rock. The closure closed freight truck traffic.

A graphic example of how cautious you need to be with standing water.

Click the YouTube video below from KING 5 TV in Seattle, reporting on a couple in Vancouver, Washington, whose vehicle was half swallowed up by a sinkhole.

After an investigation, it was discovered that a leaking underground pipe had caused a deep hole that appeared to be merely a puddle.

My reaction to standing water across any roadway has forever changed.

My natural reaction to seeing standing water is pushing through if the water seems to be a foot deep or lower. But you never know if the water is coming from a water main or a sewage failure beneath. 

If you see standing water. Back up and go around if possible. Chancing it might mean losing your car or worse.