array index out of bound may not throw exception?

[mw via Digitalmars-d-learn]

Hi,

I have thought array index out of bound always throw exceptions.
However, I just debugged a case, where out of bound array index 
didn't throw exception, and just hang the thread, which is much 
harder to debug (than exception which tells the exact error and 
source line location).

So my question: array index out of bound may not throw exception 
in D?

I tried DMD and LDC, both have this problem.

Is there any flag I can pass to the compiler to let it always 
throw exception?

Thanks.