K8060 Short-circuit protection

What will happen if you short-circuit the output?

I’m building a dj-set for on the road.
The speakers used are from DAB, 150 Watt/ 8 Ohm.
(I also have a subwoofer with 2 K8060. It works perfect. )

However, one of the K8060 is broken from the dj-set. When I disconnected the speaker from the amp (the amp was still running), the TIP142 short-circuited. The following components are broken:
D1 (1N4148)
T8 (TIP142)
R16 (47 Ohm)
R19 (0.47 Ohm)
T4 (BC547)

Before this happened, the amp was perfect. (C12, C13 are 4700uF/50V) Bias correctly adjusted.

Can you tell me what to do to prevent this from happening?

Thanks

Hard to tell what happened. This is a very robust amp, however, it cannot be made completely short circuit proof.
Make sure supply voltage is within range and make sure both power rails do not have intermittend contacts.

all amplifiers must be fed into a load while being driven its all about impedence !!!
being reflected back the power has to go somewere so it distroys the output transistor thats not conducting at the time then vice versa always swithch in a dummy load with no speakers connected
i have 2x k8060 in bridge formation in a base bin driving 500w speaker fan cooled got 360w out of them!!!

I am trying to build this circuit as a part of my college project. The big problem is that i have to construct the PCB myself and from the given manual, there are two circuits can any one please please give me some description on what each circuits do as u guys have already built it. Thanks!!! the link for the manual spaennare.se/K8060/k8060.pdf