From a comment on a blog post about whether a landline is worth it anymore:
Many folks here in San Diego ditched their landlines and it almost cost them their lives back in October of 2007 when we had the firestorm. In San Diego county we have a reverse 911 system and it dialed thousands of people at 4AM to let them know the fire was approaching. Folks without a landline had no idea the fire was coming. When I went to bed at around 10am it was 30 miles away and by morning was I was being evacuated.