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.

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.

Dmitry Kharinin, an engineer and resident of Volgograd told a local news outlet Tuesday that he saw the lightning: "It was very strong, and could be heard throughout the cabin."

Kharinin says he 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.

The plane landed hard, destroying the landing gear and igniting the engines, he said.