Ruptured main? 330 feet deep? C'mon, even if they ran the main 33' deep, it's not going to erode 300' deep. Besides, where is the broken pipe sticking out of the sides of the hole? Looks to me like they unwittingly built the town over an underground chasm and the roof finally gave out.
If it was a brick or clay main -- and a lot still are, even in the US, even today -- it would probably break off flush with the edges of the hole. But you're right that there was probably an undetected cavern beneath, and the ruptured main eroded through a couple dozen feet to the deeper existing hole.
If that happened to my house, and if I survived, I'd be mad. Not because my house was destroyed -- it's insured. But because I didn't know. I could've sunk pilings down to bedrock to support the house, drilled down from the basement, and had my own Batcave! How cool would that be?