A massive response is currently underway after a bridge collapse in Baltimore, Maryland. The U.S. Coast Guard, Baltimore Fire and Police and a number of other state agencies are responding after a container ship struck the Francis Scott Key Bridge, as there may have been 20 people thrown into the water when it broke apart. Freezing temperatures and low visibility are making it difficult for rescuers. The 1.6-mile bridge was a major thoroughfare and carried the Baltimore Beltway\Interstate 695 over the Patapsco River. The incident is being treated as a mass casualty event. A team of structural engineers will be investigating the collapse of the entire bridge. Stunning video obtained by CNN shows the structure breaking apart as it drops into the river.