Shredder's plan is to flood the Sewers of New York City with robot crocodiles. The crocodiles carried bombs within them, which he intended use to blow up the Hero Turtles' lair. April O'Neil just happened to be parked nearby in the Channel 6 newsvan, and she went to record their actions, and got caught.
Once one of the crocodiles is in position, Shredder has it detonated, which throws Splinter, Michelangelo, Leonardo, and Raphael for a loop. April, however, warns them over the radio of more incoming, and they are all destroyed, angering Saki.