Firefighters are blaming an employee's error for a flash fire that injured 13 people during a Nevada science museum's demonstration about tornadoes. Reno fire officials said a three- to five-second blaze erupted Wednesday after the museum presenter poured alcohol on a cotton ball that had been dusted with boric acid and partially ignited. The alcohol is supposed to be applied before the boric acid and the flame. The demonstration is designed to create a small tornado out of green smoke. Authorities say eight children and one adult were taken to a Reno hospital for minor burns or smoke inhalation, and four people were treated on site. One child remained in the hospital in good condition Thursday. The Terry Lee Wells Nevada Discovery Museum reopened Thursday, but the tornado demonstrations have been suspended.