Several guys lost more than 90% of their money. However, they had billions or hundreds of millions.
Lots of employees had the 401K company match in stock and lost 95% of it’s value. Prior to Enron, the company strongly encouraged officers to hold shares of stock, and many officers did this through the 401K. Despite Enron, many had not replaced the stock with another investment. AIG management (evenly lower and middle management) had stock options that went underwater and then expired. The stock dropped from $80 to under $5 and then reverse split 1 for 20. The current stock price today is $62. Divide that by 20 and you see that AIG stock is worth about $3 on a pre-crash basis. I doubt the stock will recover in my lifetime.