Witness History BBC World Service

On 31 May 1970, the Huascarán avalanche, caused by the Ancash earthquake, destroyed the town of Yungay, in Peru.

Only 400 people, out of a population of 18,000, survived.

A clown, named Cucharita, saved approximately 300 children, who were at a circus performance, by leading them to higher ground.

Rachel Naylor speaks to his son, Christian Peña.

(Photo: Statue of Christ at the cemetery overlooking Yungay, after the avalanche. Credit: Science Photo Library)

On 25 May 1963, leaders of 32 newly-independent African nations came together for the first time in the Ethiopian capital Addis Ababa.

At stake was the dream of a united Africa.

In 2013, Alex Last spoke to Dr Bereket Habte Selassie who took part in that first gathering.

(Photo: Haile Selassie, centre, and Ghana's first President Kwame Nkrumah, left, during the formation of the Organisation of African Unity. Credit: STR/AFP via Getty Images)

On 31 May 2013, a huge tornado hit an area close to El Reno in the US state of Oklahoma.

It was the widest tornado ever recorded and produced extreme winds of more than 400 kilometres an hour.

Eight people were killed, including three storm chasers.

One of the people tracking the storm was Emily Sutton, a meteorologist with KFOR-TV in Oklahoma City.

She’s a member of the station’s storm chasing team and was caught in the tornado.

She tells Rob Walker about the impact that day had on her and other storm chasers.

(Photo: Cars damaged by the El Reno tornado. Credit: Joe Raedle via Getty Images)

In August 1992, a shocking photograph of a starving, emaciated man behind a barbed wire fence of a Bosnian concentration camp stunned the world.

The picture, taken from an ITN report was of a Bosniak Muslim called Fikret Alić.

Reporter Ed Vulliamy was there when the photograph was taken.

In this programme Ed reunites with Fikret and hears how the picture, which was published around the world, eventually helped Fikret flee to safety.

This programme contains descriptions of sexual violence.

It was produced by Anna Miles.

(Photo: Fikret Alic in a Bosnian refugee camp. Credit: ITN/Shutterstock)

In 1980, a group of 16 army sergeants, led by Dési Bouterse, seized power in the small South American country of Suriname, overthrowing the government in a swift and violent coup d’état.

The coup came just five years after the country was granted independence from the Netherlands.

The country’s first president, Johan Ferrier, was forced to leave Suriname after the coup.

Rosemarijn Hoefte, professor of the history of Suriname at the University of Amsterdam, and Johan Ferrier's daughter, Cynthia, have been sharing their memories of that time with Matt Pintus.

(Photo: Johan Ferrier. Credit: Alamy)

In Stockholm in 1941, Astrid Lindgren made up a story for her seven-year-old daughter, Karin, about a young girl who lived alone and had super-human strength.

Karin named her Pippi Långstrump, or Pippi Longstocking in English.

Four years later, Astrid submitted her story into a competition and it won.

Her book, Pippi Långstrump, was published and became an overnight success.

It’s now been translated into more than 70 languages, as well as being made into more than 40 TV series and films.

Rachel Naylor speaks to Astrid’s daughter, Karin Nyman.

(Photo: Astrid Lindgren. Credit: Getty Images)