What Just Happened

I was in a ranked game about 30 minutes ago, then my entire team got disconnected all at the same time, except for me. I have no idea why they all left, we were losing, but it wasn't unwinnable. I figured they can't be a 4 queue because it was ranked, so it wasn't just them all quitting to play a different game or something. I really doubt it was a major coincidence that everyone just decided to all rage quit at the same team, especially since my team had a pretty good attitude. And I don't think it was a server issue because only my team had 4 people missing. I'm assuming it's either a bug or my team got DDosed. I have no idea what happened, I just want an explanation. Please tell me your ideas. And it could also be I'm just looking too much into a coincidence.