on my single speed commuter, the connect link pictured below, broke apart on the solid side. the side with the removable clip remained intact and I probably rode the bike for a few days before figuring out what the strange sound was that occured under load.

chain is only 6 mos old. it's been cold as ice here all month and the bike stays outside. but I'm wondering if i screwed up installing the link originally. if not, any ideas what caused it. bike is only ridden 10 miles a week.