I probably wasn’t clear. Matter isn’t destroyed, in the sense that it just disappears, but it is converted into energy. In this case, radiation.
In classical physics, matter is always conserved, and energy is always conserved. Einstein postulated that matter could be converted to energy and vice versa, so it becomes the conservation of matter/energy.
Right - but Hawking said that as matter goes into a black hole it is destroyed.
Thus, he was wrong.