[Mike Mercury]

discussed in the past, but still interesting:

the Three Sisters waves:

A group of three rogue waves, often called "three sisters," was reported in the vicinity of Fitzgerald at the time she sank. The "three sisters" phenomenon is said to occur on Lake Superior as a result of a sequence of three rogue waves forming that are one-third larger than normal waves. When the first wave hits a ship's deck, before its water drains away the second wave strikes. The third incoming wave adds to the two accumulated backwashes, suddenly overloading the deck with tons of water.

Captain Cooper of Anderson reported that his ship was "hit by two 30 to 35 foot seas about 6:30 p.m., one burying the aft cabins and damaging a lifeboat by pushing it right down onto the saddle. The second wave of this size, perhaps 35 foot, came over the bridge deck." Cooper went on to say that these two waves, possibly followed by a third, continued in the direction of Fitzgerald and would have struck about the time she sank. This theory postulates that the "three sisters" compounded the twin problems of Fitzgerald '​s known list and her slower speed in heavy seas that already allowed water to remain on her deck for longer than usual.

Originally Posted by 69camfrk

I have seen a few documentaries on that wreck, and some of the speculation was that the waves mentioned put the boat in a position where the front and aft ends were supported by the water, but the majority of the hull was "out" of the water and simply snapped in half. It would certainly explain why there was no distress call.