School alert system

Did you know that some school doesn't have school alert system? Seriously, it is highly recommended that all school should have this kind of system whether it's public or private school because the purpose of this is to notify the students and faculty staff quickly when in the event of a critical incident happens inside the school or campus. Also it can be use if there is a calamity within the area of the school and it would let the student's parents know if classes were canceled or not.