I had this happen to me at a company that I owned in the past. I got the DOL to chop the total amount due in half and then got them to allow us to pay it out over 4 or 5 years. (All without a lawyer btw...) Edit: Reason for downvotes?
Because you're bragging about screwing workers out of paid rest time.
http://www.dol.gov/elaws/esa/flsa/hoursworked/screenEE5.asp
How obscure!