If your important documents aren't already in a safety deposit box or in a fire-resistant safe, they should at least be in Fire-Resistant Document Bags. These fiberglass fire-resistant document bags protect your property deeds, passports, titles, birth certificates, cash, photos & more up to 1000 ° F.
I'm not taking any chances though. I think I can go a few steps further to completely safeguard my valuables. I'm putting all of my important stuff inside these bags, putting those bags inside a small waterproof fire-resistant safe, putting that safe inside a safety deposit box in a bank and putting that entire bank inside the fire-department which will then be guarded by an armed Terminator who guards the time portal back to the point when my valuables were still safe. That should do it.