The sign at a Portland road construction site was changed by a hacker to read "Warning Zombies Ahead!" on Wednesday morning. It originally read "Night work 8 pm-6 am. Expect delays."

City spokeswoman Nicole Clegg says the signs are a safety precaution and changing it could have led to driver distraction.

She tells The Portland Press Herald tampering with a safety device is a misdemeanor punishable by up to a year in jail and a $1,000 fine.

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