Hi, sorry for the delay! It's never too late, no worries.

They won't mess anything up, but do you remember the speakers in the train that went off wen everyone first arrived? Well, they will repeat the same message they played once more. Since there's a few NPCs floating around, the two of them are welcome to recognise the voice as this guy, since the recording will likely be easier to hear... until zombies rain on their parade, or something.

Apart from that, they can find a small, charred (from the crash) paper with a bunch of gibberish written on it. It's actually a language, but not one found on Earth!