"Avalanche," the ninth episode of season five of "The Crown," was one of the most powerful episodes of the Netflix series, and not just because actress Emma Colin aptly performed Princess Diana's instantly iconic dance to Billy Joel's "Uptown Girl." It wasn't. (Opens in new tab.) Perhaps even more potent than the marital problems rapidly bubbling up between Diana and Prince Charles is the exploration of the episodes depicted before and after her gutsy performance, concerning the avalanche that killed a close friend of the royal family in March 1988.

The tragic accident did indeed occur, and took place while Prince Charles and Princess Diana were on a routine trip with close friends and family to the swanky Klosters ski resort in Switzerland. Diana was fortunately not on the slopes that day, but Charles was. Miraculously, however, he was not caught in the avalanche. This is the true story of the avalanche and its aftermath.

Fortunately, he was on the slopes when the avalanche occurred, but it did not. Meanwhile, Diana and Sarah Ferguson, then married to Prince Charles' brother Prince Andrew, had returned to spend the day at the party chalet; according to a March 1988 report in The Guardian (opens in new tab), the palace, in a statement, Prince Charles and Lindsay, and two others in their group were standing on Mount Gottsnagrat, off the designated ski trails, when a snowfall began to descend a very steep slope.

All were able to escape the path of the avalanche except Lindsay and Patricia Palmer Tomkinson, who broke both legs in the accident. When the avalanche stopped, Charles and the rest of the group immediately began digging out the two trapped skiers. Lindsey was airlifted to a hospital near Davos, but was reportedly pronounced dead on arrival. When Charles was rescued from the slopes by another helicopter, he was reportedly "visibly distressed" and "crying," according to witnesses, including the helicopter pilot.

According to a June 1988 report in the Los Angeles Times (open in new tab), a subsequent investigation revealed that Charles was not held responsible for Lindsey's death and Palmer Tomkinson's injuries, but that an avalanche warning had been issued that day and that a very experienced skier, had willingly followed Charles down a difficult, unmarked slope, and his entire group was found responsible for the accident. [Diana told biographer Andrew Morton (opens in new tab) that she took charge of the planning because her husband was still quite upset from the accident. Prince Charles and Princess Diana, accompanied by Queen Elizabeth, Prince Andrew, and Sarah Ferguson, attended the funeral a week after Lindsay's death.

However, despite this seemingly united show of support, the accident reportedly exacerbated what was already a considerable strain on Charles and Diana's marriage. According to Tina Brown's biography (opens in new tab), The Diana Chronicle, Diana not only "blamed Charles for his recklessness in choosing such a dangerous ride," but also chose to spend the following weeks not with her husband but with Lindsay's widow Sarah Horsley. Charles, on the other hand, felt a strong sense of guilt over the tragedy and later reportedly wrote in a letter (opens in new tab), "I still have difficulty understanding why I survived and he did not."

According to Brown's book, palace housekeeper Wendy Berry wrote, "This tragedy affected their subsequent lives in several ways. Prince Charles took his sons Prince William and Prince Harry to learn to ski on the elite slopes of Klosters on numerous occasions during the 90s and early 2000s. Harry then spent most of his gap year at Klosters, and Williams' first photo with Kate Middleton (opens in new tab) was taken on a visit to the ski resort in 2004.

Since the initial broadcast of The Crown, the Queen and her family have followed precedent and refrained from publicly commenting on this and other episodes (although they are rumored to have been avid viewers of the show throughout its run). However, Lindsay's widow did speak out about the on-screen depiction of her husband's death.

Horsley, who was six months pregnant with her daughter at the time of Lindsay's death and working in the Buckingham Palace press office at the time, told The Sunday Telegraph (opens in new tab) that she contacted Netflix beforehand to avoid dramatizing the horrific accident. It's a very private tragedy for me," she said, "while the royal family will have to grin and bear it. Horsley reportedly received a "very kind" reply, explaining that while the show's producers understood her wishes, they could not grant them, but hoped she would "feel that they are treating a difficult subject with sincerity and great sensitivity."

Horsley noted that she was "horrified" to see her husband's tragic death reenacted on screen and was particularly concerned about the potential impact on her daughter (who has Prince Charles as her godfather). I wouldn't watch it because it would be too upsetting to see something like that," she said, adding, "Perhaps at some point in the future I'll watch it quietly with Alice." It will be hard. My daughter has only heard about the accident from me. She wasn't even born yet when the accident happened."