Lest you ever underestimate the capacity of killer whales to kill, the heart-stopping trailer for "Blackfish" will scare you straight. Magnolia Pictures has just released the trailer for the upcoming documentary, directed by Gabriela Cowperthwaite, which is set to hit theaters July 19th. "Blackfish" tells the story of Tilikum, a performing whale at SeaWorld that swallowed its trainer whole.

"Blackfish" goes behind the dichotomy of how we perceive killer whales, or, orcas. On the one hand, these creatures seem friendly and fascinating to watch as they soar out of the water before a crowd at SeaWorld. But on the other hand, they have the ability to kill viciously. The documentary exposes never before seen footage and interviews from the Tilikum case surrounding this hushed up scandal. The film spans the orca's fascinating nature, the cruel treatment of orcas in captivity, and the disillusionment of workers who have had their safety jeopardized by the corrupt and profitable sea-park industry.

Watch the riveting trailer below: