Memorial Day for the Liquidators and Victims of Radiation Accidents and Catastrophes is observed in Russia every April 26. This official commemorative day honors those who lost their lives in the Chernobyl disaster and other nuclear accidents. The Chernobyl disaster occurred on April 26, 1986, when a power surge led to the explosion of Reactor 4 at the Chernobyl Nuclear Power Plant, releasing significant radioactive particles into the atmosphere and affecting parts of Belarus, Ukraine, and Russia. At least 41 people died during or shortly after the accident, and between 600,000 and 1 million personnel were involved in the cleanup efforts from 1986 to 1992, exposing them to radiation. The observance was established in 1993 and was renamed in 2012 to include those who participated in eliminating the consequences of nuclear accidents. While this day is specifically recognized in Russia, April 26 is also marked as International Chernobyl Disaster Remembrance Day globally, with Ukrainian liquidators being honored on December 14.