Elon Musk said he had to 'save Twitter from bankruptcy.' Here's what would happen if it filed for Chapter 11.

• Elon Musk has floated bankruptcy as a possibility for Twitter, but had said costs are "under control."
• Twitter reportedly has roughly $13 billion in debt from a group of banks, with $1 billion annual interest payments.
• Companies can use Chapter 11 to slash debt, but it could give lenders control over its future.

Elon Musk marked his early months at Twitter's helm with mass layoffs and reports of round-the-clock work by himself and a shrunken workforce of engineers.