Pittsburgh Steelers Hall-of-Famer Franco Harris has died at the age of 72, just days before the 50th anniversary of the Immaculate Reception. Harris played for the Steelers from 1972 to 1983 and was famous for that incredible play that won the Steelers their first playoff game 50 years ago.Several events were planned in Pittsburgh in the days ahead marking the anniversary of The Immaculate Reception.The cause of Franco Harris’ death was not immediately known. “It is difficult to find the appropriate words to describe Franco Harris’ impact on the Pittsburgh Steelers, his teammates, the City of Pittsburgh and Steelers Nation,” team President Art Rooney II said in a statement. “From his rookie season, which included the Immaculate Reception, through the next 50 years, Franco brought joy to people on and off the field. He never stopped giving back in so many ways. He touched so many, and he was loved by so many.”“We have lost an incredible football player, an incredible ambassador to the Hall and most importantly, we have lost one of the finest gentlemen anyone will ever meet,” Pro Football of Fame president Jim Porter said in a statement. “Franco not only impacted the game of football, but he also affected the lives of many, many people in profoundly positive ways.”Harris ran for 12,120 yards and won four Super Bowl rings with the Pittsburgh Steelers in the 1970s, a dynasty that began in earnest when Harris decided to keep running during a last-second heave by Steelers quarterback Terry Bradshaw in a playoff game against Oakland in 1972.With Pittsburgh trailing 7-6 and facing fourth-and-10 from their own 40 yard line and 22 seconds remaining in the fourth quarter, Bradshaw drifted back and threw deep to running back French Fuqua. Fuqua and Oakland defensive back Jack Tatum collided, sending the ball careening back toward midfield in the direction of Harris.While nearly everyone else on the field stopped, Harris kept his legs churning, snatching the ball just inches above the Three Rivers Stadium turf near the Oakland 45 then outracing several stunned Raider defenders to give the Steelers their first playoff victory in the franchise's four-decade history.“That play really represents our teams of the ’70s,” Harris said after the "Immaculate Reception" was voted the greatest play in NFL history during the league's 100th anniversary season in 2020.Though the Raiders cried foul in the moment, over time they somewhat embraced their role in NFL lore. Oakland linebacker Phil Villapiano, who was covering Harris on the play, even attended a 40th-anniversary celebration of the play in 2012, when a small monument commemorating the exact location of Harris’ history-altering catch was unveiled. Villapiano still plans to attend Saturday night's jersey retirement ceremony for his former rival-turned-friend, and is just fine with the mystery that still surrounds what actually happened at 3:29 p.m. on Dec. 23, 1972."There’s so many angles and so many things. Nobody will ever figure that out,” Villapiano said. “Let’s let it go on forever.”While the Steelers fell the next week to Miami in the AFC championship, Pittsburgh was on its way to becoming the dominant team of the 1970s, twice winning back-to-back Super Bowls, first after the 1974 and 1975 seasons and again after the 1978 and 1979 seasons.And it all began with a play that shifted the fortunes of a franchise and, in some ways, a region.“It’s hard to believe it’s been 50 years, that’s a long time,” Harris said in September when the team announced it would retire his number. “And to have it so alive, you know, is still thrilling and exciting. It really says a lot. It means a lot.”Harris, the 6-foot-2, 230-pound workhorse from Penn State, found himself in the center of it all. He churned for a then-record 158 yards rushing and a touchdown in Pittsburgh's 16-6 victory over Minnesota in Super Bowl IX on his way to winning the game's Most Valuable Player award. He scored at least once in three of the four Super Bowls he played in, and his 354 career yards rushing on the NFL's biggest stage remains a record nearly four decades after his retirement.“One of the kindest, gentlest men I have ever known,” Hall of Famer Tony Dungy, a teammate of Harris' in Pittsburgh in the late 1970s, posted on Twitter. “He was a great person & great teammate. Hall of Fame player but so much more than that. A tremendous role model for me!”Born in Fort Dix, New Jersey, on March 7, 1950, Harris played collegiately at Penn State, where his primary job was to open holes for backfield mate Lydell Mitchell. The Steelers, in the final stages of a rebuild led by Hall of Fame coach Chuck Noll, saw enough in Harris to make him the 13th overall pick in the 1972 draft.“When (Noll) drafted Franco Harris, he gave the offense heart, he gave it discipline, he gave it desire, he gave it the ability to win a championship in Pittsburgh,” Steelers Hall of Fame wide receiver Lynn Swann said of his frequent roommate on team road trips.Harris' impact was immediate. He won the NFL's Rookie of the Year award in 1972 after rushing for a then-team-rookie record 1,055 yards and 10 touchdowns as the Steelers reached the postseason for just the second time in franchise history.The city's large Italian-American population embraced Harris immediately, led by two local businessmen who founded what became known as “Franco's Italian Army,” a nod to Harris' roots as the son of an African-American father and an Italian mother.The “Immaculate Reception” made Harris a star, though he typically preferred to let his play and not his mouth do the talking. On a team that featured big personalities in Bradshaw, defensive tackle Joe Greene and linebacker Jack Lambert among others, the intensely quiet Harris spent 12 seasons as the engine that helped Pittsburgh's offense go.Eight times he topped 1,000 yards rushing in a season, including five times while playing a 14-game schedule. He piled up an additional 1,556 yards rushing and 16 rushing touchdowns in the playoffs, both second all-time behind Smith.Despite his gaudy numbers, Harris stressed that he was just one cog in an extraordinary machine that redefined greatness.“You see, during that era, each player brought their own little piece with them to make that wonderful decade happen,” Harris said during his Hall of Fame speech in 1990. “Each player had their strengths and weaknesses, each their own thinking, each their own method, just each, each had their own. But then it was amazing, it all came together, and it stayed together to forge the greatest team of all times.”Harris also made it a habit to stick up for his teammates. When Bradshaw took what Harris felt was an illegal late hit from Dallas linebacker Thomas “Hollywood” Henderson in the second half of their meeting in the Super Bowl following the 1978 season, Harris basically demanded that Bradshaw give him the ball on the next play. All Harris did was sprint up the middle 22 yards — right by Henderson — for a touchdown that gave the Steelers an 11-point lead they would not relinquish on their way to their third championship in six years.Despite all of his success, his time in Pittsburgh ended acrimoniously when the Steelers cut him after he held out during training camp before the 1984 season. Noll, who leaned on Harris so heavily for so long, famously answered “Franco who?” when asked about Harris' absence from the team's camp at Saint Vincent College.Harris signed with Seattle, running for just 170 yards in eight games before being released in midseason. He retired as the NFL's third all-time leading rusher behind Walter Payton and Jim Brown."I don’t even think about that (anymore),” Harris said in 2006. “I’m still black and gold.”Harris remained in Pittsburgh following his retirement, opening a bakery and becoming heavily involved in several charities, including serving as the chairman of “Pittsburgh Promise," which provides college scholarship opportunities for Pittsburgh Public School students.Reflecting on Harris' legacy on Tuesday, before Harris' death, Steelers coach Mike Tomlin called it “an honor to be in proximity to it, to know the man involved.”Harris is survived by his wife, Dana Dokmanovich, and son Dok.___The Associated Press contributed to this report.