That was when the train suddenly stopped.

Hamazura’s body slid across the roof. He managed to stop himself and then looked around in surprise. He saw Mugino standing a good way back on the track. She must have jumped from the bridge just as he had. Her hand was stuck deep in the ground. The power cables for Academy City railroads ran through the ground. Mugino had used her power to sever the power cable in order to stop the train.

Toaru Majutsu no Index Vol.15 ch.4 pt.6