hatch

steam

protection

water

manhole

street

hot

city

main

vapor

hole

smoke

urban

metal

technology

sewer

damage

emergency

iron

central

energy

heat

construction

circle

stop

zone

tape

red

security

white

transportation

caution

warning

barrier

hazard

danger

safety

striped

restricted

restriction

attention

protect

dangerous

secured

heating

conduit

pipework

sewerage

inspection

drain

industry

pit

repair