There are some conflicting accounts on the Nedelin catastrophe. "A significant number", "Hundreds", "Scores of engineers". The closest to a concrete number I found is 74 deaths on site, but the number of these, who died in hospitals due to injuries is not available, estimates of total death toll ranging from 101 to 180. Rockets and People: Creating a Rocket Industry vol 2, page 598.
Still, these sources are rather dated, and many secret documents of Soviet Union have been revealed since. Are there any more precise estimates on the number of victims of the disaster?