The house sucked into oblivion- in Poltergeist (1982)
One of my all time favorite effect shots is the climactic destruction of the Freeling house in Poltergeist. In a matter of seconds, right in front of our eyes, the house is sucked into oblivion, leaving nothing but an empty lot.
The shot started with a plate of the real house, shot on location. The house itself was then painted out with a matte painting showing the empty lot and the neighboring houses in the background.
The imploding house itself was a 6 feet wide model, built to match the real house in every detail - that alone took four months. After countless tests it was decided that the collapse should be accomplished by attaching thick wires inside the model and simply pull it into a funnel, while tearing it apart. The model was placed over this funnel, with the camera shooting directly down. An air mover was attached, to suck away any debris.
To get the right kind of motion from the collapse, the model was shot at 360 frames per second, 15 times normal speed. More speed means more light, and this setup had so much light the crew had to wear welding glasses, and if something went wrong the model would simply have melted, or perhaps burst into flames.
After the model shoot was completed, the element required a further two months of work. Hand painted mattes were created to isolate the house and every tiny bit of debris so it could be added to the plate of the empty lot.
In a film full of impressive effect shots, this is still the most impressive. It's pure magic. Black magic surely, but magic nonetheless.