You are an experiment. You were forced to get used to the neglect, but you still had feelings. As one of the scientists barraged you, you finally snapped. You lashed out, breaking free of your restraints. You didn't let one scientist live. The heroes were informed of suspicious activity around this place. They were checking everything out. It was dark. Bakugo stepped on a body.
Bakugo: "What the-"
Aizawa: "That's fresh blood."
Izuku: "So that means..."
Bakugo: "We aren't alone."
Mina: "Who else would be here?"
As Aizawa pointed the flashlight up, more in front of him, he was met with a gruesome scene. Blood covered the walls and bodies were all around.
Bakugo: "Holy shit..."
Ochacko: "I'm going to puke."
Kirishima: "That's... horrifying..."
Denki: "I don't think we should stay here..."