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The concern is that all of the caked-on gum on the walls at the Pike Place Market may be damaging the building’s bricks.

The tradition started as people were waiting to get into the Market Theater.

Over the years, the Market has steam washed some of the walls, but this will be its first full cleaning.

Three workers wearing rain gear will shoot out water heated to 260 degrees to get the gum down.

“We love the wall and we want it to come back. It just seemed like a good time to let the wall re-emerge,” said Emily Crawford with Pike Place Market.

It's estimated there are more than a million pieces of gum on the walls.

"It's actually really disgusting. I just thought it was one wall. I didn't realize it goes all the way down," said Diego, who was visiting from the Tri Cities. After it's removed, the gum will be weighed to determine just how much was stuck to the walls.

The cleaning begins at 8:30 a.m. Tuesday. People will be allowed to stick gum on the walls again on Thursday or Friday.