Recently a guy in Utah County had a heart attack. Unfortunately, he was unable to speak to a 911 dispatcher because the phone company had a phone circuit problem. Luckily, he once worked at a hospital and was able to speak to someone there.
Incidents like this make it helpful to know what to do when you can't reach a 911 operator. So I suggest you find out if your local police department has a ten-digit emergency dispatch number and write it down. If you can't find a 10-digit emergency number, write down the non-emergency number and hopefully they'll send help when you call them.
If you're in the Fairfield, CA area the emergency number is 707-428-7373.