I wasn't one of them because I had a meeting in the morning (which was cancelled due to the weather) but once the freezing rain cleared I made it out to try my luck before working the rest of the day from a local library. Initially when we arrived my heart dropped a bit because there were only two birders present and all I saw were a couple of Common Loons in the harbour. However, a couple seconds later and I realized I was looking too far away - the bird was only about 20ft from the birders!
Needless to say, great views of this rare bird
Apparently, Thick-billed Murre used to occur semi-regularly on Lake Ontario in late fall/early winter but that hasn't been the case since the 1950s
The Birds of Hamilton by Bob Curry has a good summary of Thick-billed Murre in Ontario listing records from about a dozen years before the mid 1950s, some with fairly extensive "wrecks" of multiple birds.
[EDIT: Thanks to Glenn Coady for the following references if you are interested in Thick-billed Murre history:
Fleming, J.H. 1907. The unusual migration of Brunnich's Murre (Uria lomvia) in eastern North America. Proceedings of the IV International Ornithological Congress, pp. 528-543.
Hoyes Lloyd's review of the Birds of Ottawa:
Lloyd, H. 1923. The birds of Ottawa, 1923. Canadian Field-Naturalist 37: 101-115; 125-127; 151-156.
Lloyd, H. 1924. The birds of Ottawa, 1923 [conclusion]. Canadian Field-Naturalist 38: 10-16
Lloyd, H. 1944. The birds of Ottawa, 1944. Canadian Field Naturalist 58: 143-175.]
However, since then there have only been two documented records for Ontario:
1995: 5-6 December, Deschenes Rapids, Ottawa River, Ottawa. Found by Bruce Di Labio
1998: 29 November, Burlington Ship Canal, Hamilton. Found by Robert M. Sachs, Sheila Bowslaugh, Eleanor Sachs, and Carl J. Rothfels
The Ottawa record apparently was originally identified as a Razorbill (pretty easy to do when it isn't at your feet!) and it wasn't realized what it was until the morning of December 6. Since many birders already had Razorbill on their Ontario lists many missed out on this bird even though it was technically chase-able. Even relatively local birders missed this bird for that reason because there was only a couple hours between when its real identity was realized and the time it disappeared [edit - according to an anonymous comment it was killed by a Gyrfalcon!!].