alarm
alert
alertness
bell
break
burglar
caught
caution
crime
danger
department
electrical
emergency
equipment
fire
help
hurry
illustration
industrial
industry
intruder
isolated
law
loud
metal
mounted
prevention
protection
red
rescue
response
ring
safety
school
security
sign
simple
sound
symbol
system
urgency
urgent
vintage
wake
wall
warn
white