San Francisco's homelessness crisis is so dire, there's now a 911 alternative to get people on the street instant help - here's how it works

San Francisco is dealing with the harsh reality of a homelessness crisis that's gone from bad to worse. In 2017, more than one in 100 homeless Americans lived on the city's streets.

Tired of feeling helpless, Jacob Savage and Neil Shah created an app called Concrn that lets people send an alert whenever they see a person experiencing a mental health crisis, homelessness, or an issue with substance abuse. The app's dispatcher sends a civilian response team trained in empathy to help get that person back on their feet and connect them with relevant support services.

We recently shadowed a Concrn responder on their shift. Here's what it was like.