Soviet hydrogen bomb creator dies by suicide

Russian nuclear physicist Grigory Klinishov, co-creator of the Soviet Union's first two-stage hydrogen bomb, has been found dead in his apartment in Moscow, local media reported on June 22.

Emergency services told TASS, that Klinishov, 92, died by suicide. His body was found on June 17 at his central Moscow apartment on the Kosmodamianskaya embankment by his daughter, who also found a note beside him in which he said goodbye to his loved ones, the daily newspaper Kommersant reported.

Klinishov was one of the creators of RDS-37, the first Soviet two-stage thermonuclear bomb—also known as a hydrogen bomb, according to Newsweek.

The bomb was tested in 1955.

Born on October 30, 1930, in modern-day Russia's Ryazan region he was an engineer-physicist, candidate of physical and mathematical sciences. In 1962, he received the Lenin Prize— the most prestigious award in the Soviet Union in the field of science, technology, literature, and art.

According to Kommersant, Klinishov was grieving over the death of his wife and he had his own health problems. Russian news agency Regnum reported that the nuclear physicist's daughter talked to her father shortly before his death. After their conversation, she left the apartment for a couple of hours and found his body when she returned home. In his note, he reportedly asked for forgiveness from his daughter.

Klinishov moved in his early childhood to Moscow and studied at the Moscow Engineering Physics Institute (now the National Research Nuclear University MEPhI). He later worked as an engineer in Sarov, in Nizhny Novgorod Oblast, in a department headed by physicist Andrei Sakharov, who was one of the developers of the first Soviet hydrogen bomb. Klinishov was appointed the leading researcher of the department in 2002.

When the RDS-37 was first tested at the Semipalatinsk Test Site—the primary testing venue for the Soviet Union's nuclear weapons—it shattered glass within a 125-mile radius and damaged buildings in 59 settlements, as well as killing a soldier and a three-year-old girl and injuring several dozen others.

The bomb exploded in the air 1.5 kilometers (0.9 miles) above the ground, resulting in a blast far stronger than was expected. Approximately seven minutes after the RDS-37 detonated, the height of the radioactive cloud was 13 to 14 kilometers and its diameter was nearly 30 kilometers. The power of the thermonuclear explosion was estimated at 1.7 megatons.

Later in his career, Klinishov went on to develop several other types of thermonuclear bombs.

An investigation is reportedly being carried out into the scientist's death.