(AP) — Although a Virginia woman became the third wing walker to die in two years when a fiery crash killed her and a pilot at an Ohio air show, those in the business insist such fatal accidents are rare.

Forty-four-year-old wing walker Jane Wicker and 64-year-old pilot Charlie Schwenker were killed Saturday in a crash that was witnessed by thousands of horrified spectators at the Vectren Air Show near Dayton. The cause is not yet known.

John Cudahy, president of the International Council of Air Shows, says from 1975 to 2010 just two wing walkers were killed in the U.S. But since 2011, three wing walkers have died, including Wicker.

Cudahy says the spike appears to be a coincidence and that the business is “not quite as dangerous” as it seems.