In her lifetime, Elizabeth II had a chance to go through many crisis moments. In 1966, a tragedy struck the village of Aberfan in South Wales when a mine collapsed, killing 116 children and 28 adults.

Her Majesty recognized the decisions made after this as the main mistake in her life.

Everything turned out extremely unsuccessfully: having received news of the disaster, Elizabeth could not find the strength to make a public statement, and refused to come to the village out of a sincere desire not to distract everyone from the ongoing rescue work.

Later, she admitted that she deeply regretted her decisions and she should have gone to the village mourning for the dead children as soon as possible. During the visit, Elizabeth burst into tears, which she almost never did in public.

Of the 240 people who were at the school that day, 144 died: 116 children and 28 adults. The victims were taken to a nearby hospital, while the bodies were piled up in a local chapel, which was temporarily designated as a mortuary. The excavations continued for about a week: some families found their dead relatives only a few days after the disaster.

In the Netflix series The Crown, there is also an episode dedicated to the tragedy in Aberfan.

Unsurprisingly, the episode dedicated to one of the worst tragedies in recent British history was the most emotionally heavy in the series.