Gov. Chris Gregoire on Friday directed that all state and U.S. flags at state agency facilities be lowered to half-staff Sunday, in recognition of national Patriot Day.

Gregoire is encouraging all government entities, citizens and businesses to join in this recognition. Flags should remain at half-staff until the end of the day Sunday, or first thing Monday morning.

Patriot Day occurs on Sept. 11 of each year in memory of those killed in the 2001 terrorist attacks.