I was just playing on a trade_plaza server, enemy team was spawn camping as usual.
So, I built a dispenser, sentry, and teleporter entrance (all are level 3) in my spawn.
After like 5 minutes or so, the sentry and dispenser just randomly blow up without a killfeed showing how it died (no one was even shooting at the dispenser anyway). But, my teleporter entrance was still there, unharmed.
This happened to me before earlier in the same trade_plaza.