Railroads switched from flagmen to automatic block signals long ago, so it's time to freshen up some metaphors, particularly the shopworn red flag of danger. If an editorial writer is trying to make the point that some earlier incident should have given regulators a clear warning about some company's recklessness long before things blew up, he could toss out the red flag and say instead, “There was a torpedo right there on the track but the agency rolled over it and kept on going.” Laid on a rail to warn of sure danger ahead and detonated by pressure, torpedoes were flat, round noisemakers that would detonate with a cannon-like report at the first touch of a locomotive wheel. An engineer might miss noticing a man on the right of way waving a red flag, but he wouldn't miss the sound of a torpedo.
"That project was a complete train wreck that took out all the investors" could be freshened up to "That whole project was a snakehead." In the early decades of railroading, a rail was not the sturdy round-topped bar of rolled steel we know today, but a long board laid on its edge and topped along its length with a wrought-iron strap, nailed on. Sometimes one end of a strap worked loose and bowed upward as a train was rushing by. If snagged by running gear the iron bar would fly loose and smash through the wooden floor of a moving coach, killing or maiming all passengers within reach, however wealthy. So when a big pyramid scheme goes bust and takes out hundreds of families' savings, that's a snakehead.
"His reputation is shot" could be railroadized to "His reputation is on the hammer track." That's a salvage siding used for tearing apart old boxcars and locomotives.