Mushers and theirs dog teams during the Sedivackuv long race, Orlicke Mountains, Czech Republic on January 28, 2016. The 240 Km (150 miles) race is a multi-day event, but was canceled today, two days early, because of poor snow conditions in the region. (Photo by David Tanecek/CTK via ZUMA Press)

A participant peeks from his costume before the start of the the annual London Pantomime Horse Race in Greenwich, Britain December 13, 2015. (Photo by Neil Hall/Reuters)

Participants compete during the Strong Race event near Tukums, Latvia, May 3, 2015. More than 4,000 people participated in this 9 km endurance race with 33 different obstacles. (Photo by Ints Kalnins/Reuters)

A 10 km prologue dog sled race on the eve of the 2018 Beringia dog sled race in Russia' s Far East; the prologue race is part of the 2018 Russian Winter Dog Powered Sports Cup in Petropavlovsk-Kamchatsky, Russia on March 4, 2018. (Photo by Yuri Smityuk/TASS)

Pete McLeod of Canada flies in formation with Nigel Lamb of Great Britain, Martin Sonka of the Czech Republic and Kirby Chambliss of the United States during a Recon flight prior to the seventh stage of the Red Bull Air Race World Championship over the Hoover Dam on October 09, 2014 on the border between the U.S. states of Arizona and Nevada. (Photo by Joerg Mitter/Red Bull via Getty Images)

“A prototype lunar lander was destroyed on August 9, 2012, at Kennedy Space Center during its first free flight”. – James Dean via Florida Today

Photo: Morpheus Ground Level Hot Fire. Photo Date: April 2nd 2012. Location: VTB Flight Complex; Photographer: Joe Bibby

Competitors take part in the Red Bull Crashed Ice Cross Downhill World Championship in Marseille, France, January 14, 2017. (Photo by Jean-Paul Pelissier/Reuters)

A plane carrying a wing walker crashed at an air show and exploded into flames Saturday, killing the pilot and stunt walker, authorities said. The crash of the 450 HP Stearman happened at around 12:45 p.m. at the Vectren Air Show near Dayton in front of thousands of horrified spectators. No one else was hurt.

Photo: A wing walker performs at the Vectren Air Show just before crashing, Saturday, June 22, 2013, in Dayton, Ohio. The crash killed the pilot and the stunt walker instantly, authorities said. (Photo by Thanh V. Tran/AP Photo)