The question Lost important office documents. How to properly handle the situation? was closed for lacking a goal we can address. I have edited the post to include a useful question. This situation can arise commonly enough in the workplace, so knowing how to deal with it would be useful to several people.
The natural reaction to this situation from a lot of people would be to panic and try to hide it, which will only make matters worse. Hence, an answer stating what to do instead would be beneficial.
Please cast reopen votes if you agree.