An Orange Line train passenger jumped off a bridge and into the Mystic River and dozens of other passengers evacuated through the windows of the MBTA train after it caught on fire on a bridge in Somerville, Massachusetts. Subscribe to WCVB on YouTube now for more: http://bit.ly/1e8lAMZ Get more Boston news: http://www.wcvb.com Like us: https://www.facebook.com/wcvb5 Follow us: https://twitter.com/WCVB Instagram: https://www.instagram.com/wcvb5/