The Globe reports that Modern Continental, the largest Big Dig contractor, filed for Chapter 11 bankruptcy protection this morning. The filing comes amid news that the firm owes between $500 million and $1 billion to creditors. Additionally, the U.S. Attorney's office filed fraud charges against Modern Continental late Friday afternoon. Some Big Dig contractors thought money would just fall from the sky. Instead, they got ceiling tiles.

Michael Femia contributed to this post.