Stephen Hawking was a pretty amazing person, don't you think?
yes he was
Did you see the movie, "The Theory of Everything?"
no i didn't but would like to see it
It was a great movie about his life. It is pretty fascinating if you like science. It is interesting to learn about his life with ALS and how he persevered with it.
ALS, is that the same as Lou Gerich disease?
Yes, it is also known as motor neurone disease or Lou Gehrig's disease.
I wonder if that is what he eventually died of
I'm not sure, but I think so. It undoubtedly contributed to his death. He lived a pretty amazing life even with his disability. It is refreshing to see someone persevere in the face of such obstacles. 
i agree, sad he died but he lived a fulfilling life with his disability and you cannot ask for more