Continue writing the next sentence.

How to clean a gas fireplace 
Turn the gas off. 
Before you begin cleaning your gas fireplace, you must first make sure you turn the gas valve to the " off " position. If you leave the gas running, it could cause a dangerous gas leak in your house.
The gas valve is typically on the wall next to the fireplace. Allow a few minutes for all the gas to leave the piping in the fireplace.