emergency fire flash flashing hazard light lights police policia siren strobe strobe light warn warning caution eye eye protection goggle goggles mechanic protection safe safety shop sign access-denied advice alert appropriate-behavior appropriate-behaviour black boating boats care communicating communication danger dangerous directing direction helpful information informative informing not-allowed not-permitted prohibited prohibition restricted restriction restrictions risk risks risky rocks rocky shallow signs symbol symbols warning-sign water waterside words yellow beware flake lubricity red road security snow triangle winter astronomy comet doom fast graphic portent shooting space speed stars universe velocity design drown info lake pond communicate emergency exit escape exit fire escape closed closed road sign detour message obstacles redirection road sign