Moscow — A survivor of the Russian commercial airliner that crash-landed in Moscow on Sunday, killing 41 people, says a flash of lightning was heard moments before the plane began its emergency descent. "It was very strong, and could be heard throughout the cabin," Dmitry Kharinin, an engineer and resident of Volgograd, told a local news outlet Tuesday.

Kharinin said he saw the lightning but did not witness a direct lightning strike on the Russian-made Sukhoi SSJ100. However, he speculates that the electromagnetic discharge of the lightning may have disabled plane systems.

Investigators are still working to understand what happened to cause the plane to ignite in a fireball upon landing. A lightning strike is one theory.

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The plane landed hard, destroying the landing gear and igniting the engines, Kharinin said. The aircraft burst into flames, trailed by smoke.

Video posted on a state-run news website appeared to show the chaos inside. A woman can be heard screaming "we're on fire" and a man called for calm amid the frantic sound of seat-belts unbuckling.

Passengers who could fled down slides at the front of the plane, some with luggage. But dozens of others never made it out. Among them is 22-year-old Jeremy Brooks of New Mexico. His former boss told CBS News the recent college graduate was going to Russia to work as a fly-fishing guide.