What events deter people from traveling?

• 9/11
  Many people were scared to fly after 9/11. In addition, there have been rough economic times in recent years. However, millions of Americans continue to travel abroad each year.
• the 2004 tsunami
  Many people were scared to fly after 9/11. In addition, there have been rough economic times in recent years. However, millions of Americans continue to travel abroad each year.
• Hurricane Katrina
  Many people were scared to fly after 9/11. In addition, there have been rough economic times in recent years. However, millions of Americans continue to travel abroad each year.