MARYSVILLE – A car-size sinkhole on southbound Highway 529 is an obstacle in the way of this morning’s commute from Marysville to Everett.

Drivers who use Highway 529 to avoid having to get on southbound I-5 will be forced to use the crowded freeway until at least 9 a.m., if only for a couple of minutes.

The sinkhole appeared between Ebey Slough and I-5. That means southbound drivers will be able to get back on Highway 529 as soon as they cross the slough.

Repairs were expected to start Wednesday evening and last until at least 9 a.m. today, possibly going as late as noon, said Travis Phelps, a spokesman for the state Department of Transportation.

A culvert failed, allowing a hole that’s 12 feet long, 5 feet wide and 5 feet deep to form under the highway, Phelps said. The hole in the asphalt, or what was visible to drivers, was significantly smaller than what formed underneath the road.

“It kind of formed this cavernous void,” he said. “It’s big.”

No one fell in or was injured, Phelps said, adding that maintenance crews discovered it Wednesday morning. Workers put a steel plate over the hole, allowing the morning commute to continue.

The repair work was being rushed to minimize the effect on commuters, but also to avoid the tide, Phelps said.

“We’re going to throw a hefty chunk of equipment at this,” Phelps said Wednesday. “We’re going to have three backhoes out there.”

Even a small traffic interruption can lead to hours-long lines when it comes to commuting into Everett from the north end, commuters say.

When the Highway 529 bridges over the Snohomish River open or are repaired, traffic backs up on Marysville’s city streets, especially if there’s work happening on the U.S. 2 trestle.

Reporter Lukas Velush: 425-339-3449 or lvelush@heraldnet.com.