Washington's Supreme Court says a 20-day unpaid suspension was an appropriate punishment for a Port of Seattle employee who left a noose hanging in the workplace.

In 2007 a 70-year-old white co-worker asked Mark Cann to put away a rope. Instead, in what he characterized as a joke, Cann tied it into a noose, saying that it was to put the co-worker "out of his misery."

The noose was observed and reported by a black co-worker with whom Cann had a recent falling out. The Port of Seattle fired Cann, but an arbitrator reinstated him with a 20-day suspension.

A King County Superior Court judge found that too lenient and boosted the suspension to six months.

But in a unanimous decision Thursday, the Supreme Court reinstated the arbitrator's award. The high court held that although Cann's acts were "ignorant and unacceptable," at a time when many working families live month-to-month, 20 days without pay was a significant punishment.