The 1980 Plesetsk launch pad disaster was the explosion of a Vostok-2M rocket carrying a Tselina-D satellite during fueling at Site 43/4 of the Plesetsk Cosmodrome in the town of Mirny in the Soviet Union at 19:01 local time (16:01 UTC) on 18 March 1980, two hours and fifteen minutes before the intended launch time.

It took a few days to remove all the dead from the pad area during which time small fires continued to burn.

[1][2] The official investigation responsible for determining the cause of the disaster headed by Leonid Smirnov assigned blame to the crew that was killed at the site of the fire by specifically stating the official cause as "explosion (inflammation) of material soaked in liquid oxygen as a result of unauthorized actions of one of the members of the ground crew."

The investigative committee was under political pressure to blame the launch crews, many of whom were dead and couldn't defend themselves, rather than the workforce at the Khrunichiev plant in Samara where R-7 vehicles were assembled.

[1][3][4] The disaster was not reported in Soviet media at the time and was not publicly admitted to until the glasnost era nine years later.