Always make sure that the grill is used in a safe place, where kids and pets won't touch or bump into it. Keep in mind that the grill will still be hot after you finish cooking, and anyone coming into contact with it could be burned.
If you use a grill lighter, make sure you don't leave it lying around where children can reach it. They will quickly learn how to use it.
Never leave the grill unattended, as this is generally when accidents happen.
Keep a fire extinguisher or garden hose nearby.
Ensure that the grill is completely cooled before moving it or placing it back in storage.
Ensure that the grill is only used on a flat surface that cannot burn, and well away from any shed, trees or shrubs.
Clean out the grease and other debris in the grill periodically. Be sure to look for rust or other signs of deterioration.
Don't wear loose clothing that might catch fire while you're cooking.
Use long-handled barbecue tools and flame-resistant oven mitts.
Keep alcoholic beverages away from the grill; they are flammable!

In 2007-2011, U.S. fire departments responded to an average of 8,800 home and outside fires. These 8,800 fires caused an annual average of 10 civilian deaths, 140 civilian injuries and $96 million in direct property damage.
More than one-quarter (27%) of the home structure fires involving grills started on a courtyard, terrace or patio, 29% started on an exterior balcony or open porch, and 6% started in the kitchen.
In almost half (43%) of the home outdoor fires in which grills were involved, half (51%) of the outside gas grills, and 29% of gas grill structure fires, the fire started when a flammable or combustible gas or liquid caught fire.