Balloons are inflated at the Bristol International balloon fiesta in south west England August 6, 2015. The largest hot air balloon festival in Europe takes place over four days and is in its 37th year. (Photo by Toby Melville/Reuters)

Crew members inflate a balloon during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

Balloons take off during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

Crowds watch as tethered balloons are illuminated by their burners during the night glow evening event on the first day of the Bristol International Balloon Fiesta at the Ashton Court estate on August 6, 2015 in Bristol, England. Now in its 37th year, the Bristol International Balloon Fiesta is Europe's largest annual hot air balloon event in the city that is seen by many balloonists as the home of modern ballooning. (Photo by Matt Cardy/Getty Images)

Hot air balloons rise into the morning sky from the Bristol International Balloon Fiesta main arena at the Ashton Court estate on August 7, 2015 in Bristol, England. (Photo by Matt Cardy/Getty Images)

Balloons take off during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

A balloon flies over a camping site in Bristol during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

A hot air balloon named “The Ship” (L) is seen tethered during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

Balloons fly over Bristol during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

A balloon flies during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

Crowds watch during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

Balloons fly at the Bristol International Balloon Fiesta in south west England August 6, 2015. (Photo by Toby Melville/Reuters)

Balloons are illuminated by their burners during a dusk display at the Bristol International balloon fiesta in south west England August 6, 2015. (Photo by Toby Melville/Reuters)

Balloons fly over Bristol during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

A balloon flies over Clifton Suspension Bridge in Bristol during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

Balloonists fly during a mass launch at the Bristol International Balloon Fiesta in south west England August 7, 2015. (Photo by Toby Melville/Reuters)

Balloons fly at the Bristol International Balloon Fiesta in south west England August 6, 2015. (Photo by Toby Melville/Reuters)

Balloons fly at the Bristol International Balloon Fiesta in south west England August 6, 2015. (Photo by Toby Melville/Reuters)