Hit 500 loaves on the same starter and the jar cracked the day after

I keep a little notebook where I tally every loaf that comes out of my oven, mostly so I stop blaming the recipe when something goes wrong. Last Thursday the count hit 500, which took me about 3 years of baking 3 or 4 loaves a month in my kitchen here in Toledo. I did the math and that jar of starter has been fed over 1,500 times, which is a lot of flour for one glass jar from the dollar store. The next morning I pulled it out of the fridge and there was a hairline crack running from the rim halfway down the side. Nothing leaked yet but I could feel it with my thumbnail, so I moved the starter to a plastic quart container and tossed the jar. The weird part is I felt bad about it, like the jar had been there for all 500 loaves and never got any credit. My wife pointed out it was a 2 dollar jar and I should get over it, which is fair. Now I'm wondering if glass jars just fail after enough thermal cycles, or if I did something dumb like set it on a cold counter while it was still warm. Has anyone else worn out a starter jar, and how long did yours last?