Kern KB, et al. - Given the importance of every minute in the treatment of out-of-hospital cardiac arrest (CA), researchers investigated if a decrease in call-to-arrival times, leading to earlier CPR and defibrillation, could be achieved with a coordinated effort of alerting trained local neighborhood volunteers (vols) simultaneously with 911 activation of professional EMS providers. In a retirement residential neighborhood in Southern Arizona, encompassing approximately 440 homes, a program of simultaneously alerting CPR- and AED-trained neighborhood vols and the local EMS system for CA events was developed. In multiple days of mock CA notifications and responses, 15 vols and the closest EMS station were involved within this neighborhood. In this neighborhood, the closest EMS station was at a distance of 3.3 miles while the volunteers averaged 0.3 ± 0.2 miles from the mock CA. This indicates that local neighborhood volunteers vs the EMS service were geographically closer and took significantly less time to arrive at the mock CA scene. With the volunteers, the estimated time savings from call to arrival was 4–6 min.