The SS Californian

Just after midnight on April 15, 1912, once it became clear that the RMS Titanic was bound shortly for the bottom of the Atlantic, her officers tried to signal a ship about 10 miles away, seeking her assistance in offloading their passengers to a safe rescue. While that ship, the merchant steamer SS Californian, did other things during her war-truncated 14 year career, literally falling asleep at the helm while the Titanic sank will forever be her most memorable legacy. You can read more about the ship here:
The SS Californian

The Californian was a smaller and slower ship than the Titanic, and when captain Stanley Lord made the decision to stop for the night rather than risk crossing a dense ice field in moonless darkness, radio operator Cyril Evans saw no reason to stay up late. Around 11:30 he attempted to warn the Titanic, then racing at full speed deeper into the Labrador Current, about the dangerous ice ahead, and was greeted by this response from the big liner: "Shut up, shut up! I am busy; I am working Cape Race!" Ten minutes later Titanic would come to a wounded halt after ripping open too many watertight compartments to stay afloat on an iceberg. Sometimes timing and politeness, or lack thereof, is everything.

Would lives have been saved if Evans had stayed up a little bit longer and heard the initial "SOS" from Titanic? Certainly, but it's hard to imagine things ending well. Titanic was carrying a small town's worth of people, well over 2,000, and by the time Californian would've arrived at the site, Titanic would only have had another hour or so left to go on the surface, probably not enough time to transfer everyone over. By the time the Titanic's officers launched flares in an attempt to rouse the attention of those on the Californian, it was probably already too late to make a difference. Still, the facts are maddening, and it seems like the Californian should've done something to help, however ineffective it might have wound up being.

Three years later, this littler ship would join her bigger cousin below the ocean waves, this time some distance west of the island of Crete. World War I was an awful, violent time, and the Californian was jut another victim. Her life was shorter and more tragic than it should've been, but at least these kinds of accidents and sinkings don't happen often any more.