"...the start of what ended it all."
Listening to such a line, Lith got more interested in knowing what had happened. He had a rough guess about it after listening to the old man speak.
A demonic beast was worshipped by the people. It profited from the people's faith and in return, it sent things to them to keep their faith intact. Then, two travellers stumbled here from his own world and tempted the beast into probably causing the demise of everyone in this world.
This was Lith's rough guess. The place indeed seemed like a temple and since everything was in ruins and there were no people in this world apart from some Tier 5 and below beasts, this was the basis of what Lith made his guess.
Despite having a rough guess, he didn't interrupt the old man and simply nodded his head, indicating that he was listening. The old man backed off and then started sipping on tea.