Calgary police are investigating a violent assault at the Calgary Stampede that left three people hospitalized late Tuesday night.The incident took place around 11:05 p.m. on Tuesday near the Euroslide on the Stampede Midway. Officers responding to the initial call found a man in medical distress after being stabbed and rushed him to hospital in life-threatening but stable condition.Shortly afterward, police located two additional stabbing victims — a youth near 17 Ave. S.E. and Macleod Tr., and a man near Erlton St. S.W. and 27 Ave. S.W. Investigators later determined both had also been assaulted during the same Midway incident. They were transported to hospital in serious but stable condition.Police do not believe the assault was random. No arrests have been made and the suspects remain at large.Investigators say witnesses were likely present during the altercation and that some may have captured the attack on cellphone video. Anyone with footage or information is urged to contact police at 403-266-1234 or provide tips anonymously through Crime Stoppers at 1-800-222-8477, at www.calgarycrimestoppers.org or via the P3 Tips app.