Working smoke alarms save lives, cutting the risk of dying in a home fire in half. The most dangerous fires are in homes without working smoke alarms. Most people who are killed in house fires die from carbon monoxide and smoke inhalation, not burns. Have an escape plan if fire breaks out in the home - “two ways out” should always be available.
Smoke alarms should be in place in every sleeping room, outside each separate sleeping area and on every level of your home, including the basement.
For smoke alarms with replaceable batteries, replace the batteries once a year or sooner if chirping. Completely replace smoke alarms that have life-long batteries every 10 years old or if chirping.
Also read about Evacuation