But within a few hours, another fire was discovered at a transit center drop box across the Columbia River in Vancouver.
He urged voters who dropped their ballots in the transit center box after 11 a.m. Saturday to contact his office for a replacement ballot.
The workers will have instructions to simply observe the ballot boxes and not confront anyone.
Washington and Oregon, which are both vote-by-mail states, have long used ballot drop boxes.
The fire suppression systems inside the ballot drop boxes in Washington and Oregon were designed to activate when the temperature inside reaches a certain point, coating ballots with a fire-suppressing powder.
Monday afternoon, voters dropped off their ballots at the new drop box that replaced the one that had been set on fire in Portland.
In Phoenix last week, officials said roughly five ballots were destroyed and others damaged when a fire was set in a drop box at a U.S. »