Soviet military aircraft were usually of a higher order of reliability than civilian equipment. The IL-76 has been used around the world by a lot of countries.
That said, it could be that there was bad maintenance; or, maybe
somebody fired a hand-held missile at it...
LOL, I fully expected that to be true...military assets were probably far more important to the government than any single Soviet commercial airliner carrying a bunch of proletariat schlubs...