Earlier this year, researchers at the University of Tokyo accidentally created the strongest controllable magnetic field in history and blew the doors of their lab in the process.

Instead of using TNT to generate their magnetic field, the Japanese researchers dumped a massive amount of energy—3.2 megajoules—into the generator to cause a weak magnetic field produced by a small coil to rapidly compress at a speed of about 20,000 miles per hour. This involves feeding 4 million amps of current through the generator, which is several thousand times more than a lightning bolt. When this coil is compressed as small as it will go, it bounces back. This produces a powerful shockwave that destroyed the coil and much of the generator.

To protect themselves from the shockwave, the Japanese researchers built an iron cage for the generator. However they only built it to withstand about 700 Teslas, so the shockwave from the 1,200 Teslas ended up blowing out the door to the enclosure.