[laughter] >> What started as a normal journey on a train quickly turned into a disturbing confrontation. At first, everything appears calm with transit workers sitting inside the carriage. Within seconds, the conversation turns into a physical confrontation. The workers get to their feet as the situation escalates. Then, suddenly, one person goes down. What exactly caused the confrontation and what happened before the camera started recording? This is the kind of footage that leaves more questions than answers.