A huge sinkhole in Harbor, Ore., led to the closure of Highway 101 on Friday, Jan. 28. The hole is larger than any the area has seen in 20 years. (YouTube/Dave Lovell)

A “monster” sinkhole larger than any seen in southwest Oregon in 20 years forced the closure of a span of coastal highway this week.

The Oregon Department of Transportation cordoned off the five-lane stretch on Thursday after the formation of a sinkhole that measures 80 feet in diameter.

“It’s a monster for sure,” said Jared Castle, Oregon DOT spokesman for southwest Oregon. “This is a very unusual event and is a sinkhole of a magnitude that we don’t see but once every couple decades.”

Thursday’s void emerged next to another sinkhole that measures 50-feed wide. It will take an estimated 65,000 cubic yards of material to fill the holes and shore up the adjacent slope, he said.

Kyle Rice, a local drone hobbyist, uploaded multiple aerial videos of the holes to YouTube.

The new sinkhole is the largest seen in southwest Oregon since 1996. A sinkhole that formed early one November morning that year swallowed two tractor-trailers, plunging them 50 feet below the road they were on that dark night. No serious injuries resulted.

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The same was true on Thursday: No one was injured and no cars were swallowed by the new void, which opened up in a parking lot between the Fireside Diner and a Chevron gas station, along U.S. 101 in Harbor, Oregon.

The original sinkhole opened up on Dec. 13 after a period of heavy rain and has swelled to its current size from an initial depth of seven feet and width roughly the size of a volleyball, Castle said. Crews have been working to clear a resulting blockage in an underground drainage, which has forced water flows to find another way to the sea from the nearby hills and thereby created other such voids, he added.

[Florida sinkhole reopens two years after it swallowed a sleeping man and killed him]

“Basically it’s like flushing a bunch of Legos down your toilet,” Castle said.

Sinkholes have proven to be an unpredictable problem for local authorities throughout the world, forming suddenly and wreaking havoc. The formation of a sinkhole resulted in the closing of a stretch of road in Washington, D.C., on Friday.

This post has been updated.

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