A single Lego brick can support 375,000 other bricks before collapsing!
Lego are incredibly strong. A BBC program called More or Less asked Open University's engineering department to find out how many Lego bricks it would take staked on top of each other to destroy the bottom brick.
They used a hydraulic testing machine and they determined that the maximum force that a 2x2 Lego brick can take is 4,240 newtons. Since those 2x2 Lego bricks have a mass of 1.152 grams, it would take a stack of 375,000 bricks to cause the bottom brick to collapse. That would be a stack 3,591 meters (11,781ft) high!
Learn more about Lego at the source.