54 people have been killed and dozens injured after the roof of a large store collapsed in Latvia's capital, Riga. The initial collapse was followed by a second cave-in just as the first responders at the scene were helping the victims. Three rescuers and firefighters were killed by the second collapse. The video shows third collapse on Saturday. No one was injured. FULL STORY: br RT LIVE br Subscribe to RT! br Like us on Facebook Follow us on Twitter Follow us on Instagram Follow us on Google+ br RT (Russia Today) is a global news network broadcasting from Moscow and Washington studios. RT is the first news channel to break the 1 billion YouTube views benchmark.