An Iowa woman was killed when an explosion at a gender reveal party sent debris flying, police said. Deputies arrived at a house in Knoxville, Iowa, about 40 miles outside of Des Moines, around 4 p.m. Saturday, and pronounced the 56-year-old woman dead on the scene. Investigators determined that an explosion during the gender reveal announcement caused the woman’s death, the AP reports. It’s unclear what caused the explosion. The woman’s identity has not yet been released.