We had the same kind of shelf collapse as seen here, with less drastic consequences.
I went and found some nice 90-degree pins at the store, but noticed a small problem when installing.
The pins on the new supports are slightly longer than the old ones (old pins are 5/16", new are 7/16"). So when installed the nice L-bracket doesn't sit flush with the wall. Is this a problem? I'm guessing it should sit flush so that the wall helps the pin-hole support the weight. Pics at the end.
Should I just drill the pin-holes to be slightly deeper (assuming the walls are deep enough - these holes are on built-in shelves so it's not immediately obvious if they are) If I don't do that, should I file the pins down? Look for similar supports with slightly shorter pins? Or are they fine as is?