People stand under a giant Czech flag as they arrive to light candles at the base of a statue of St. Wenceslas to commemorate the death of former Czech President Vaclav Havel on December 18, 2011 in Prague, Czech Republic. Havel, who led the Velvet Revolution that forced communist rule in Czechoslovakia to crumble in 1989, died in the early morning today in his sleep at the age of 75. (Photo by Sean Gallup/Getty Images)

Army paratroopers carry the casket of Private Howard at the Wellington Cathedral on December 21, 2010 in Wellington, New Zealand. Private Howard was serving with the British army when was killed by friendly fire from a US Air Force plane in Helmand Province, Afghanistan earlier this month. Private Howard is the fifth NZ-born soldier to be killed in action in Afghanistan. (Photo by Marty Melville/Getty Images)

Sikhs wield swords during their clash inside the complex of the holy Sikh shrine, the Golden Temple, in Amritsar June 6, 2014. Sikhs wielding swords clashed inside the compound of their religion's holiest shrine on Friday, the 30th anniversary of a controversial raid by security forces that flushed out separatist militants holed up in the temple. REUTERS/Munish Sharma

The zombies, cowgirls, and witches were out in force Saturday night on Clematis Street as thousands of people came to Moonfest to celebrate Halloween. They came from Broward County, Boynton Beach, Wellington, Port St. Lucie, and as far away as Germany and Sweden. Photo: Joe Smith, 60, Boca Raton. (Photo by Thomas Cordy/The Palm Beach Post)

Faces adorn crosses placed in the Garden of Remembrance of some of Britain's armed forces members who have died in Afghanistan in the Garden of Remembrance outside Westminster Abbey at the official opening of the Royal British Legion's Field of Remembrance on November 5, 2009 in London, England. (Photo by Alastair Grant-Pool/Getty Images)

Death Muammar Muhammad Abu Minyar al-Gaddafi (7 June 1942 – 20 October 2011) in Misrata on October 20, 2011. The veteran strongman was killed on as new regime forces crushed the last pocket of resistance in his hometown Sirte, the National Transitional Council said. (Photo credit should read MAHMUD TURKIA)

Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

A Ukrainian serviceman who fought in Debaltseve is seen near Artemivsk February 19, 2015. Fighting raged in eastern Ukraine on Thursday despite European efforts to resurrect a still-born ceasefire, a day after pro-Russian separatists who spurned the truce forced thousands of government troops out of a strategic town. (Photo by Gleb Garanich/Reuters)