From NHL.com:

Married to the hockey legend for 56 years, Colleen, also known as "Mrs. Hockey," had suffered since 2002 from Pick's Disease, a degenerative neurological disorder that causes severe dementia.

This is huge and terribly depressing for all of us lucky enough to have met Mrs. Howe or simply had their lives touched by her.

My brother and I clearly remember the Hartford (and New England!) Whalers meet-and-greets where the entire Howe family would partake. They lived in our town and shopped in our stores. Quite the honor. You always knew who she was: strong and fiercely devoted to Gordie and their children; she was the defacto agent for all three.

My most sincere wishes to a wonderful family on a great loss.