Jammers only have a 30-foot range
Nobody is going to die because of a jammer. Besides, cellphones lose their signal for alot of reasons: underground, inside big buildings, inside rooms with lead paint on the walls, dead battery, etc. I think someone with a cellphone that can't get a signal, and who has an emergency call to make, would look for a landline a short distance away. That's how it was done 10+ years ago.