Is pilot alerted of any physical or structural failures? Current crew alerting system messages, I believe, are displayed basing on the software detection of the failures basing on the sensor information.


What kind of structural failures can occur to an aircraft in flight? (I know one case an engine got separated and communicated to pilot as just 'engine fail' instead of 'engine broken or something that might indicate a physical disconnect'). The had me wondering what other structural failures are possible when in flight. When I say structural failure, I am talking about a physical disconnect, bent, etc. Is there a (remote) chance that a structural failure can be caused in an airplane. 
If at all a structural failure occurs in the middle of flight, is there any mechanism to let pilot know about it.
At the risk of sounding like a smartass, the alert is generally in the form of a loud BANG! or CRACK! followed, at best by different handling characteristics and increased wind noise/vibration, at worse, departure from controlled flight.