One dive on my last trip got a bit more exciting than intended. 24 minutes into the dive at 18m depth my first stage blew off its end cap and whatever is supposed to be behind it. The result, a pandemonium of noise and air bubbles. My buddy had already been alerted by the noise and we weren't too far apart. I gave the out-of-air sign, although it must have been pretty obvious, and her octopus got its first life action. After I closed my main valve to get rid off the noise and conserve the remaining air in the tank, we ascended to 5m and buddy-breathed the 15 minute swim back to the exit point.
This is something you always hear about and it was part of the solo diver training I took last year. But in the end you never know how you respond when it really happens. In this case all other conditions were favorable. Good visibility, no current, familiar dive site, 40 dives in the preceding days, and an experienced buddy within short distance. But it is a good reminder to be trained, prepared, and equipped to deal with whatever situation a dive throws at you.
Here is a picture of the regulator and its intact sibling. It was serviced just before the trip but I'm now looking for a new reg and a new dive shop to take care of it. The escaping high-pressure also broke the octopus but I hope that can be fixed.