Life-threatening events are common in today's hospitals, where an increasing proportion of patients with urgent admission are cared for by understaffed, often inexperienced personnel. Medical errors play a key role in causing adverse events and failure to rescue deteriorating patients. In-hospital cardiac arrest outcomes are generally poor, but these events are often preceded by a pattern of deterioration with abnormal vital signs and mental status. When hospital staff or family members observe warning signs and trigger timely intervention by a rapid response team, rates of cardiac arrest and mortality can be reduced. Rapid response team involvement can be used to trigger careful review of preceding events to help uncover important systems issues and allow for further improvements in patient safety.