A state commission has been formed to investigate the cause of the accident in the Arkhangelsk Region that killed five members of the Russian Federal Nuclear Center — All-Russian Scientific Research Institute of Experimental Physics (Sarov, Nizhny Novgorod Region), the center's Director, Valentin Kostyukov, said.

"A state commission is looking into the causes of the accident, and will draw the relevant conclusions," Kostyukov told Channel 16/Sarov Television in a recording available on the network's official YouTube account.

The victims were Alexei Vyushin, Yevgeny Koratayev, Vyacheslav Lipshev, Sergei Pichyugin and Vladislav Yanovsky. All five have been recommended for state decorations.

Kostyukov went on to say that according to preliminary reports, staff members did everything they could to avert the incident.

"Judging by the preliminary analysis, we believe that they were fighting to get the situation under control. Unfortunately, they did not succeed in their efforts," he said.

There was an explosion followed by a fire during tests of a liquid-fueled rocket engine at a military testing range operated by the Russian Defense Ministry on Thursday, August 8. The Defense Ministry initially said that two people had been killed. Later Rosatom reported that five of its employees died while testing a liquid-fueled rocket engine. Both the Defense Ministry and local authorities insisted that there had been no rise in radiation levels.

On Sunday, following the death of the five members of the Russian Federal Nuclear Center — All-Russian Scientific Research Institute of Experimental Physics, two days of mourning were declared in the city of Sarov. A resolution of the city administration declared that they lost their lives "on a mission of national significance."

The Russian Federal Nuclear Center — All-Russian Scientific Research Institute of Experimental Physics is part of Rosatom's weaponry division. It is a major Russian research center working on military and civilian applications, as well as conducting research. According to its website, the center's main objectives include ensuring the reliability of Russia's nuclear arsenals. The Sarov nuclear center works on improving the technological specifications and effectiveness of Russia's nuclear weapons.