Why is one such a bad number? It is because when the date has this number in it, some bad thing always happens. Let me give you some examples. There midnight in Taiwan. The earthquake was very horrible. That night, there were about three thousand people that died in that accident. Many houses collapsed and the mountains moved. 　
America was attacked by terrorists on September 11 this year. The terrorists crashed into America's pentagon with an airplane. The terrorists used airplanes to hit many tall buildings in America. There were bombs inside the buildings. When the airplanes hit the tall buildings, the tall buildings and the airplanes exploded. About six thousand people died. How terrible that is! I think the terrorists were crazy. People say that the American emergency number is 911, so the terrorists chose September 11 to attack America. There was a big typhoon on July 11 this year in Taiwan. It's name was Toraji. Many cities were flooded. Some people died because of landslides. These dates all this "one" number. I really don't think "one" is a good or lucky number. So we have to be careful on dates with this number.