"He was trying to manipulate the ley line that ran under that tower," Neville continued, almost wistfully. "He reckoned he could channel his anger right through it, make it so hot that Ron would be roasted alive on the spot, if Harry could redirect the line to him. It might have worked as well. But the line grew so white-hot that the tower foundations actually melted, which pretty much undermined the stone work and it all collapsed down on top of Harry. He was buried underneath all the debris. It took ten of the house-elves three hours working in tandem to free him."