Lindsay Heimbach goes airborne while sledding down a hill on Mt. Lemmon December 27, 2008. (Photo by James Gregg/Arizona Daily Star)

Measuring just five feet at its widest point, the ultra-thin home was unveiled in the Polish capital of Warsaw on Sunday, October 21, 2012. Photo: The Keret House is squeezed into the space between two apartment buildings in Warsaw. There's a four-inch gap between the apartment buildings to either side. A perforated steel facade was used to allow in more light. (Photo by Andrea Meichsner/The New York Times)

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)

Passengers travel in an overcrowded train in the eastern Indian city of Patna, February 23, 2010. (Photo by Krishna Murari Kishan/Reuters)

A Muslim dervish sings a traditional Sufi song near a rally for the Mawlid al-Nabi holiday, marking the birthday of Islam's prophet, Muhammad, in Lahore, Pakistan, Sunday, November 10, 2019. To mark the holiday, thousands take part in religious processions, ceremonies and distribute free meals to the poor. (Photo by K.M. Chaudary/AP Photo)

German car manufacturer BMW presents the “Vision Next 100” concept car during the 100th anniversary celebrations in Munich, Germany, Monday, March 7, 2016. (Photo by Matthias Schrader/AP Photo)

Labourers pour molten iron into a container at a foundry in Xiangfan, Hubei province in this July 2, 2010 file photo. Iron ore is enjoying its biggest rally in years, outpacing copper and oil so far in 2016, but still weak forward prices show it may be tough to stretch the bullish outlook. Improving steel prices in top market China are helping fuel iron ore's climb as producers gear up for a seasonal uptick in demand. Yet there is no shortage of doubters who see gains in the bulk commodity as fleeting given a large glut and challenges for China's economy. (Photo by Reuters/Stringer)

Seven year old Hungarian herding dog Derci runs along the Olympiaberg hill during stormy weather in Munich, southern Germany, Monday, January 4, 2016. (Photo by Matthias Balk/DPA via AP Photo)