Montreal police launched an investigation after a man in his 50s was killed in a violent fight Wednesday.The victim was found unconscious by police officers around 8 p.m. in the city’s St-Michel neighbourhood. He was later pronounced dead at the scene.Police say a conflict occurred between the man and another individual, who fled the scene. It’s not clear what led to the escalation.An arrest was made early Thursday, according to an update by police. No details were provided about the suspect.The case was transferred to the police department’s major crimes unit. Investigators were expected to speak to witnesses and forensic identification technicians were at the scene.The man’s death marks the city’s 23rd homicide of the year.