This is unimaginably tragic.
The team did release a statement on the matter, though (below):
When Marvel surprised fans with their slate of NINE upcoming projects in Phase 3, they also showed them an exclusive video.
Even though we just got the Avengers: Age Of Ultron trailer this week, they already put together a super-teaser for the third (and fourth) Avengers movie!
And the Guardians Of The Galaxy are in it!