You as an American citizen enjoy a special right that citizens of other countries do not- The Right to Own Firearms. With this special right comes great responsibility. It is your responsibility to safely store, operate, and maintain your firearm(s). It is you the firearm owner who must ensure that unauthorized persons or untrained individuals cannot gain access to your firearms.
You the firearm owner must learn and obey all laws, federal, state and local which pertain to firearms. That includes laws on purchase, possession, transportation, and use of the firearms you own or control.
Firearms are neither inherently safe nor unsafe, by themselves. When a firearm is misused, it becomes unsafe. Gun owners must take full responsibility to learn and practice safe gun ownership at all times. Technically a loaded firearm left alone and unattended without human intervention the gun will not function. Eventually it will rust becoming inoperable and the ammunition will eventually decompose. Only when outside forces such as a human or primate type hand picks up the gun pointing the muzzle in an unsafe direction and/or manipulates the guns action does it become dangerous.
You must make sure unauthorized persons do NOT access your firearms!