After Jessica jokingly mentions they need to release the air out of her lungs so her body will not float to the top, Garrett stabs Megan through the chest with a tire iron, killing her for real.
After Jessica jokingly mentions they need to release the air out of her lungs so her body will not float to the top, Garrett then goes to the trunk of the car and grabs a tire iron. Then stabs Megan through the chest with the tire iron, killing her for real.