I found a story that reminds us to have backups to our backup plans. Let me just yank out the relevant part:
Wellman said the 911 call was received after the apparent shooting. He said the home’s phone line was cut during the burglary forcing the homeowner to call from a neighboring residence.
Having a cell phone is a good idea. Pick up a cheap used one and turn it on. Even if it’s not authenticated with whatever carrier it’s locked to (in other words you don’t have a cell phone plan) the phone can make emergency calls. For instance before I configured my Palm Pre to my Sprint account it would allow me to call 911 and Sprint customer service. All modern cell phones have this capability. Keep one around just in case some hood decides to cut your phone line before entering the premises. You should also keep that defensive firearm handy either way as that backup plan isn’t easily bypassed by invaders.