San Francisco's homelessness crisis has gone from bad to worse.
In 2017, more than one in 100 homeless Americans lived on the city's streets.
Now, a new app called Concrn lets people help.
They can send an alert whenever they see a person in crisis.
Such problems include homelessness, substance abuse, or a mental health crisis.
The app's dispatcher sends a civilian response team trained in empathy.
They help get that person back on their feet, connecting them with support services.