Stairway 13 had been killing people for a decade before the 1971 disaster. In September 1961, two spectators died in a crush on the same exit stairway, the one closest to Copland Road subway station. In September 1967, eleven people were hospitalized after another incident. In January 1969, twenty-nine were injured. The stairs provided almost no freedom of movement during peak crowd flow -- many supporters were lifted off their feet entirely, carried along by the press of bodies with no control over their pace or direction. Rangers had spent £150,000 on improvements, but the fundamental problem remained: over 80,000 people trying to leave through exits designed for a fraction of that number.

The Old Firm match drew more than 80,000 fans. In the 90th minute, Celtic took a 1-0 lead through Jimmy Johnstone. Then, in the dying seconds, Colin Stein equalized for Rangers. As thousands of spectators streamed down Stairway 13 after the final whistle, someone near the bottom of the stairway fell. The collapse cascaded upward. People toppled onto those ahead of them, and the crowd behind, unable to see what was happening, kept pressing forward. Bodies piled up. Initial speculation suggested that fans leaving early after Celtic's goal had turned back when Stein scored, colliding with those exiting. The official inquiry found no truth in this -- everyone on the stairway had been moving in the same direction.

The scale of loss among young people made the disaster especially devastating. Of the 66 who died, 33 were under twenty. Thirty-one were teenagers. The youngest victim was nine-year-old Nigel Pickup from Liverpool. The only female victim was eighteen-year-old Margaret Ferguson of Maddiston, Stirlingshire. Fifty-seven of the dead, including Charles Dougan, a 31-year-old boilermaker from Clydebank, died from traumatic asphyxia -- their lungs compressed by the weight of the bodies around them until they could no longer breathe. More than 200 others were injured.

In May 1974, Sheriff James Irvine Smith ruled that "the said accident was due to the fault and negligence of the defenders, Rangers F.C." after hearing evidence in a civil damages case brought by Dougan's widow. The finding came after the court reviewed the long history of incidents on Stairway 13 that Rangers had known about for years. The disaster also prompted the UK government to commission Lord Wheatley's inquiry, whose findings became the basis for the Guide to Safety at Sports Grounds -- the "Green Guide" -- first published in 1973 and still the foundation of British stadium safety regulation.

Manager Willie Waddell, shaken by what he had witnessed, drove the complete reconstruction of Ibrox. He visited Borussia Dortmund's Westfalenstadion for inspiration, and over the following decade, three sides of the ground were replaced with modern all-seater stands. By 1981 Ibrox held 44,000, expanded to 50,000 in the 1990s, and eventually earned UEFA five-star status. The transformation was a direct response to tragedy, turning a ground with a history of crushing deaths into one of Europe's most respected stadiums. Scottish folk singer Matt McGinn wrote "The Ibrox Disaster" as tribute. A memorial now stands at the stadium, bearing the names of all sixty-six.