according to the Chimney Safety Institute Of America, more than 20 thousand chimney fires are reported every year. The reason is a buildup of creosote, usually from burning green wood.
That's why it's important that you get your chimney inspected every year, or after you burn a cord of wood. Creosote is a tar like material that builds up in the chimney and even worse, if the chimney is cracked, that creosote can get into the cracks, catch fire and set the house on fire. That can be avoided if the homeowner has the chimney inspected and cleaned by a certified chimney inspector.
The inspection will let the homeowner know if the chimney needs to be repaired, or if there is a buildup that could cause a fire. It could be the best hundred dollars or so you'll ever spend.