So, I'm an attorney, and just for fun the other day I traced certain language in a deed for a house back to the early 1800s. But it occurred to me that this relied on the Registry having suffered no major disasters in the past 200+ years. So that got me thinking of fires like the Great Chicago Fire, or the like. City-engulfing conflagrations not occurring during wartime. Specifically, I want to know about all the legal documents that went up in smoke. Are there chain-of-title issues because the Registry burned down in 1906 in San Francisco? How much was business disrupted not by loss of life or facilities, but by loss of contracts and correspondence in the aftermath of the Great Fire of London?
Feel free to pick a particular disaster and go from there, to narrow the scope. I'd imagine stuff like this is less of a big deal now with electronic storage and backups, so I don't expect property ownership in New Orleans to be disrupted greatly by the flooding. But in the past, how did they deal with these paper records disappearing into smoke?
In general terms, the records are reconstructed as best they can be, and that's given official recognition (usually with some legal procedure for later challenges).
In the case of the Chicago Fire of 1871, the managing partner of one of the city's private title insurance firms recognized the danger and opportunity presented as the fire approached, and sent individual volumes of Chicago Title & Trust's abstract plant, big books containing copies of the official cadastral records, off with trusted employees to various parts of the city where they'd be safe (less than a quarter of the city was burned). The official records remained in the courthouse and were destroyed, but the Chicago Title records were used to recreate county land records.