(Portland, OR)  --  Alaska Airlines is offering lower fares today on flights between Portland and Seattle following yesterday's deadly Amtrak train derailment in Washington state.  The airline says they're lowering fares to 99 dollars each way to aid travelers who would normally take the train.  The lower fares were offered yesterday, as well.  At least three people were killed and about 72 people were injured when an Amtrak Cascades train derailed and spilled onto southbound I-5 during rush hour traffic yesterday morning.