REFILE-How $5 billion of debt caught up with Toys 'R' Us

Sept 20 (Reuters) - Toys "R" Us Inc has been making $400 million in interest payments on its debt every year, largely due to its $6.6 billion leveraged buyout in 2005. This week, it succumbed to its debt burden, leading to the biggest bankruptcy of a U.S. retailer since that of Kmart in 2004.