Thanks Nate for the reply.

Yes, very funny. And of course I have an excuse. I don't defend
all steel. You can make anything substandard for strength and durability, even in steel. Cell seem to have a history of "good value" bikes that fail when used as commuters. Eg:
viewtopic.php?f=12&t=17764viewtopic.php?f=41&t=17766I suppose if you scape the bottom of the barrel for parts, you are going to get some failures long term.
It looks like the crack was propagating under the crank. To me, that is the most dangerous type of fault as you can't see the crack forming. Steerers have the same problem.