Where to find cell phone assistance for the elderly?

In Peoria, IL. My father is 95, my mother 93..I need to get them a cell phone in case of emergency..the have a landline. my father is in nursing care as he has been ill and my mother lives independently nearby..how do I get the a free cell phone.i live in Missouri and would like to check on my father while in the nursing care facility..Christine..daughter.