The crater threatened to swallow up houses in the Seattle neighborhood.
On Nov. 11 1957, a massive hole swallowed part of Ravenna Boulevard between 16th and 17th Avenues Northeast.
The hole appeared when a sewer line broke and took out thousands of cubic yards of earth. Families in 10 houses next to the crater were evacuated out their back doors for fear their homes would fall in.
A Nov. 15, 1957, Seattle Times article described the hole as 60 feet deep, 120 feet wide and more than 200 feet long.
A graphic with the story conveyed impressive size of the hole, which also took down a 30-foot light pole and a large chestnut tree. Sewer service in the area was cut off for 10 days until an emergency bypass could be opened. John Marshall Junior High was temporarily closed for lack of sewer, water and heat, so kids gathered at the barricades to gape at the sinkhole.
The article said the sewer line was the largest in the city and was built with a brick lining. Parts of it were 145 feet below street level.
J.J. Ross, a foreman who helped dig the sewer line, told The Times that the part under Ravenna Boulevard was the most treacherous part of the 1910-1911 job.
“We’d dig a little bit and then have to line it with timbers to keep the earth from moving,” said Ross. “Then after the sewer was built, we had to fill it all back in and tamp it down hard.”
The line runs under Ravenna Boulevard and crosses the University of Washington campus to the Lake Washington Ship Canal. It then goes west along the canal, getting bigger as other lines join it, until it ends at Magnolia’s West Point.
The repairs cost $2 million. Grout was injected into the quicksand and about 3,000 feet of the sewer was lined with steel piping, according to a 1959 Times article.