PulsePoint is an app for the web, iOS, and Android that alerts of any active incident in the county relating to Fire and EMS. Allegheny County is one of many counties nationwide that participate in this. Below is the link to the web app. Select Allegheny County as the agency, and see whats active near you.
Pulsepoint can also alert anyone who is CPR certified of a cardiac arrest in your vicinity.
PulsePoint, Enabling Citizen Superhero's™