"The most recent estimated death toll, released by Roscosmos on the 50th anniversary of the accident and originating with agency engineer Boris Chertok, was that 126 people had died, but the agency qualified the number by saying that the actual number could be anywhere from 60 to 150 dead."
The Nedelin catastrophe was an ICBM test run of a rocket with hypergolic fuel that exploded on the launch pad; there was the 1980 launch pad explosion of a (military) sattelite launcher that killed 44 people and injured 43. The Russian version of the article says that hydrogen peroxide filters were produced with catalytic materials, this was later fixed after another launch almost failed in the same manner (it doesn't say how that blast was avoided), initially they suspected an action of the ground crew to have causes the blast in 1980. Both blasts were kept secret until Perestroika in 1989. both explosions were on rockets with hypergolic fuel.
The Russian wikipedia article also has a list of 'other failures' - these are fires in an ICBM silo in Russia in 1960 - eight dead; the US had a fire in a Titan II bunker in 1965 that killed 53 and another one in 1980 that killed one man; also Brazil had a fire of a liquid fueled rocket that killed 21, also on start preparations. (and another blast in Plesetsk in 1973 that killed seven http://www.plesetzk.ru/index.php?p=1973&d=doc/disaster - wikipedia doesn't list everything)
Rocket fuel can be very dangerous stuff! At least liquid methane/oxygen aren't hypergolic.
"The most recent estimated death toll, released by Roscosmos on the 50th anniversary of the accident and originating with agency engineer Boris Chertok, was that 126 people had died, but the agency qualified the number by saying that the actual number could be anywhere from 60 to 150 dead."