(White Center, WA)  --  King County sheriff's deputies say a masked man wielding a hatchet was shot and killed as he attacked a store clerk at a 7-11 in White Center, Washington.  Authorities say a customer who was in the store around 5:45 yesterday morning pulled his gun and shot the assailant as the attacker swung the hatchet at the cashier.  Investigators say the customer has a permit to carry concealed weapons.  No names have been released.