On April 22, 1986, the Chernobyl Nuclear Power Plant in the Soviet Union suffered a catastrophic meltdown in Reactor No. 4. The explosion released large amounts of radioactive particles into the atmosphere, which spread across Europe. The disaster killed at least 30 people immediately and caused long-term health effects, including cancers and birth defects. The Soviet government initially attempted to cover up the extent of the damage, but the incident became a global concern. The disaster remains the worst nuclear accident in history.