"I was wondering about that, but sort of figured that I hadn't disappeared from the timeline. We still remember the others, who are all from earlier years," Ron said, half to himself. Then he answered the questions in turn, except for the big how. "No Hermione, and that. So, in timeline order, there's Regulus from 1979, Sirius from 1980, Remus from '83, Tonks from '96, and Narcissa from '98. And us three from '03, though different months. That's new."
He took a breath, because he wasn't Hermione who could forget to breathe when there was information to share, then continued. "No one here did this, best we can figure is that it's Hogwarts' itself. Harry, there's no Ministry to contact. There's nothing. There are no wizards left. They all died somewhere around 2030, which is eight years ago from this time. Something catastrophic happened, we're working on the exact specifics but between newspapers, the ghosts, and the house-elves, it looks like they were trying to use Muggle science to fix the baby problem, and it had the unintended consequence of killing everyone off." Which was horrific, but the details were still spotty.
"So yes, for lack of a better word, we're trapped here." He turned to Draco. "Your mother is fine."