The pilot of a Russian passenger plane that erupted in a ball of fire on the runway of Moscow's busiest airport, killing 41 of the 78 people aboard, said lightning led to the emergency landing, Agence France-Presse reported.
Investigators on Monday were working to understand the causes of the blaze after the Sukhoi Superjet-100 returned to Sheremetyevo airport shortly after takeoff on Sunday evening.
Pilot Denis Yevdokimov told Russian media the aircraft lost communication and needed to switch to emergency control mode "because of lightning" on the Aeroflot flight to the Arctic city of Murmansk.
He did not specify if the plane was struck directly.
"We managed to restore communication through the emergency frequency on our radio connection. But the link was only for a short time and kept cutting out. ... It was possible to say only a few words," he told The Komsomolskaya Pravda newspaper.
Videos on social media showed the plane crash-landing and then speeding along the runway with flames pouring from its fuselage.
People could be seen leaping onto an inflatable slide at the front and running from the blazing plane as columns of black smoke billowed into the sky.
Another video shot inside the cabin showed roaring flames outside the window and passengers crying out in panic.
Yevdokimov said he believed the plane burst into flames on landing, most likely because of full fuel tanks.
Several of the 78 people on board said they believed lightning was the cause of the tragedy, which came at the end of several days of public holidays following Workers' Day on May 1.
Passenger Pyotr Yegorov told media: "We had just taken off when the plane was hit by lightning. ... The landing was very hard, we almost passed out from fear.
"The plane bounced on the tarmac like a grasshopper and burst into flames on the ground."
According to The Associated Press, the plane reportedly did not jettison fuel before the landing, as is common procedure. It was not clear why the crew did not do that.
Aside from the dead, nine people were hospitalized, three of them seriously injured, authorities said.
Russian President Vladimir Putin offered his condolences to the victims' loved ones and said the investigation into the disaster "should be as thorough as possible".
The jet took off from Sheremetyevo at 6:02 pm local time and the crew issued a distress signal shortly afterward, officials said.
The aircraft's black boxes have been found and handed over to investigators, the Russian Investigative Committee said on Monday.
In a statement, the committee said it is trying to determine the cause of the deadly plane fire and will consider the qualifications of the pilots, the dispatchers and technical inspectors, Xinhua News Agency reported.
Transport Minister Yevgeny Dietrich said there were no plans to ground the Superjet-100 model, Reuters reported.
