White coals mean high heat, not cold ashes. After cooking, place hot coals in a heavy metal container with a lid, or pour water on coals and stir them to extinguish. In 1989, a Boulder apartment building was destroyed by a fire started by hot coals discarded in a plastic trash can left on a wooden deck. Recently in Boulder County, a fire started by hot charcoal destroyed a home. The grill was placed next to wooden siding and under the eaves of the house.
Propane grills are dangerous when they leak.
Check the valves and connections by spraying soapy water on the them. Bubbles indicate gas escaping and loose connections. Clean the fire bricks to remove grease and food residue that will cause your fire to burn too hot. Always use both charcoal and propane grills outdoors in a well ventilated area to prevent carbon monoxide poisoning from invisible fumes. Flammable liquids should be stored away from structures, where pilot lights can ignite fumes.