Many people find it difficult to consider even the possibility of witnessing a sudden death. Few know what to do if such a situation occurs. Lives are lost daily nationwide from incidents involving heart attack, drowning, choking or electric shock. The steps taken to aid the victim seconds following such an incident can mean the difference between life and death. Cardiopulmonary resuscitation (CPR) is the best training to have to try to help someone in an extreme situation when that person has stopped breathing and their circulation has stopped. Learning this basic first-aid technique can help you give a friend, a loved one or a stranger a second chance for life. The heart and lungs work together to circulate oxygen throughout your body. If your brain is deprived of oxygen more than four minutes, there's a good chance you'll suffer brain damage. After 10 minutes, your chances of surviving drop to one in 100. The CPR method taught is a three-step process which is as simple as ABC. The rescuer must first establish an open Airway before determining if the victim can breathe or before breathing for him. If the victim is not breathing, the rescuer must start rescue Breathing. Checking for a pulse to gauge Circulation, and providing circulation of needed via cardiac compression, is the third step. CPR training also includes instruction in the skills necessary to properly care for a victim with an obstructed airway. Once the details are mastered, CPR is not difficult. But the details are important because, even when performed properly, CPR provides only 25 to 35 percent of the body's normal blood flow. If performed improperly, cracked ribs, rib separations or damage to internal organs can occur. The National Safety Council recommends professionally administered CPR training for all persons.