It actually doesn't work like this.
It actually doesn't work like this.

Anyone calling with an emergency was met with a busy signal early Tuesday evening.
Baltimore’s 911 system crashed, leaving 311 as the only available resource for emergency calls. Using social media alerts from the city as a guide, it looks like the outage lasted for more than an hour.
https://twitter.com/BaltimoreOEM/status/742881128374226944
https://twitter.com/MayorSRB/status/742902906504941568
There wasn’t an immediate reason given why the system crashed. According to the Baltimore Sun, neither police nor 911 system operator Verizon could provide a cause on Wednesday morning.