building escape fire fire escape ladder safety stairs communicate communication danger emergency emergency exit exit hazard sign warning architecture construction corkscrew stairs escape route escape way fire exit flight of winding stairs grate grated helical metal security shape shapes spiral spiral stair spiral staircase stair staircase wentletrap helix red barbed wire cat military zone pet runaway Canary Wharf high rise steps bar bars bent iron prison rust rusty shadow stone black color colour silhouette sky step Asia blue colored colorful colors coloured colourful colours escapes fishmonk green pattern patterned patterns primary rainbow rainbows repeat repeating same Singapore spirals stripe striped stripes stripy yellow Dirt dog escaped farm fence grass road rural sheep