At least three workers were killed at Russia's biggest standalone steel plant today when the roof of a gas purifying facility collapsed and buried them under tonnes of debris.
The roof collapsed when workers were dismantling equipment at Magnitogorsk, a huge steel mill in the foothills of the Ural mountains.
One more worker may have been killed, a regional emergencies ministry spokeswoman said, adding the accident happened because of "violations of safety rules".
Officials at Magnitogorsk, which used to assemble parts for the Soviet army during World War II, was unavailable for comment.
Most big Russian steelmakers have invested heavily in upgrades of their Soviet-era equipment in recent years to keep up with international production standards.