Complex sentence: As soon as the villagers came to know about this miracle, they thronged to the well and tried to deepen the well further but were thwarted when the swayambhu idol (the self-manifested) of Lord Vinayaka emerged from the swirling waters.
Split into simpler sentences: As soon as the villagers came to know about this miracle, they thronged to the well and tried to deepen the well further. But their attempt proved futile because the swayambhu idol (the self-manifested) of Lord Vinayaka emerged from the swirling waters.