A combination photograph shows revelers dressed in "Dia de Muertos" or "Day of the Dead" themes as they pose for photos while taking part in the Greenwich Village Halloween Parade in the Manhattan borough of New York October 31, 2015. (Photo by Carlo Allegri/Reuters)

A musician plays his violin next to a depiction of La Santa Muerte (Saint Death) at a shrine during Day of the Dead celebrations in Ciudad Juarez, Mexico, November 2, 2015. (Photo by Jose Luis Gonzalez/Reuters)

Academy Award-winning actor and comedian Robin Williams has died at 63. The cause of death is thought to be suicide by asphyxiation.

Stray dogs stand on tombs in Diamond Hill cemetery in Hong Kong, China, 04 April 2017. According to the lunar calendar, the Qingming Festival is observed on 04 April . The Qingming Festival, also known as Tomb-Sweeping Day, is marked by Chinese people by going to the cemetery to cleaning up tombs, bring flowers, and making offerings to their ancestors. (Photo by Jerome Favre/EPA)

s*x workers, wearing decorative skull masks, march through the streets in downtown Mexico City, Friday, October 28, 2016. The women march with candles to an altar dedicated to their departed colleagues, many who died violently at the hands of their customers. This annual procession, tied to the Day of the Dead festivities, has taken place for more than 20 years. (Photo by Eduardo Verdugo/AP Photo)

Mortsafes were contraptions designed to protect graves from disturbance. Resurrectionists had supplied the schools of anatomy in Scotland since the early 18th century. This was due to the necessity for medical students to learn anatomy by attending dissections of human subjects, which was frustrated by the very limited allowance of dead bodies – for example the corpses of executed criminals – granted by the government, which controlled the supply.

Demonstrators wear skull masks during an anti government protest, as Chile's President Michelle Bachelet delivers a speech inside the National Congress, in Valparaiso city, Chile May 21, 2016. (Photo by Ivan Alvarado/Reuters)