https://www.avweb.com/blogs/insider/disaster-A320-sfo-229272-1.html http://www.mercurynews.com/2017/07/...ggered-greatest-aviation-disaster-in-history/ https://aviation-safety.net/wikibase/wiki.php?id=196616 Basically, although a go-around is not a big deal, in this case there's a piquant detail: the crew did not add 2 and 2 together until an unidentified entity pointed it out to them and the tower. Even so, they came within 130 ft of another aircraft - basically passed right on top at about a wingspan altitude. Pilots seem to be dismissive in comments and do not appear to appreciate how close the call was. The most similar call in my practice was when I taxied for departure at Taos, NM, and someone lined up with me. At first I didn't believe what I'm seeing and they came pretty low, but when I blinked my landing light at them, they deftly side-stepped to the runway (I don't remember now if they landed or went for a go-around). It was in bright daytime. Considering what the Taos airport looks like, it seems absolutely impossible -- runway is much wider and the markings are clearly visible. That was strange!