Garages are a helpful way to protect your vehicles, tools and other items from the elements. They provide a fairly safe environment that is easy to access with large objects like cars and trucks. Today, many garages have automatic openers. This is incredibly convenient as you do not have to get out of your car every time you pull up to your closed garage. You can simply press a button to open and close the door.
While highly convenient, this also poses a danger. With manual garages, you can open and close them at will. They stay closed when you lock them, but are otherwise very easy to move. With automatic garage door openers, however, everything must be done through one of the buttons. You cannot manually open the door without overriding the control mechanism. While this is good for keeping things safe inside your garage, it can also be quite dangerous.
Garage door openers generally have a sensor near the bottom of the door way. This sensor is meant to stop the door from closing if there is someone or something in the way. This is a very useful safety feature that, unfortunately, does not always work. When these sensors fail, there is nothing stopping the garage door from crushing a person beneath it. This is incredibly dangerous as the person will not be able to push the door off of him or herself.