Thanks. Yes, it was a heart attack. The shit of it all is that he was already in the hospital for a few other issues that were seemingly under control. The poor guy was suffering from congestive heart failure, lung disease and kidney failure. He'd been in ill health for this past year, and it's been expected that he wouldn't be around for two much longer. He had hurt his back which put him in two weeks ago, and because of some other contributing factors his ability to walk was in serious doubt. He seemed ready to tackle it, but in the end a heart attack took his life. I think he was just ready to go.
The hardest thing for me personally (something my girlfriend is clutching to as a sign that we were supposed to find each other when we met) is that our birthday is the same day in July. It was a neat thing at first, but it's going to be a tough one this year.
He was a great guy, but at least I was able to forge a few memories before he checked out. Have a few beers, or beverage of choice this weekend for the old man!