A 71-year-old security guard is suing the Los Angeles Rams ... claiming the NFL org.'s negligence led to him suffering "catastrophic" injuries during a violent fan brawl at SoFi Stadium last year.
The man -- ID'd in the lawsuit as Robert Leahey -- says the incident happened back on Dec. 8, 2022 during the Rams vs. Raiders "Thursday Night Football" game ... when he was hired by Contemporary Services Corporation to help assist people in large crowds and help "maintain an orderly atmosphere."
At around 6:30 PM inside the Inglewood stadium, however, Leahey says a "large fight broke out" between L.