Scientists couldn't study tornadoes in 1925. The word tornado was banned since 1886, when the last major tornado struck. Sirens were invented, but the Government didn't let people sound them. Talking about tornadoes would cause panic among the public. ``To us, it was just a storm.'' said Mary Bell Melvin, a survivor of the Tri-State Tornado of 1925. ``We didn't even know the word tornado,'' she said.