On 10/17/01, the Mariners lost Game 1 of the ALCS to the Yankees.
On 10/17/00, the Mariners lost Game 6 of the ALCS to the Yankees.
On 10/17/95, the Mariners lost Game 6 of the ALCS to the Indians.
This would've carried a little more weight had I thought to post it yesterday, but, man, October 17th sucks.