Word spread quickly around Russia about explosions in the sky over Siberia, resulting in conspiracy theories and hysterical fears.

Earlier today, the local Ural news agencies reported that a bright spot, reportedly a meteor with a long, shiny tail, appeared in the sky at about 9:30 a.m. It zipped across in a few seconds, causing massive explosions that blew out thousands of windows and broke roofs and walls.

As the numbers of people with damaged ear drums, bruises, and cuts grew from 400 to 950, the ministry of emergency affairs hurried to say that they had sent text messages to everybody in Chelyabinsk to warn them about the explosion in the sky, if after the fact. But there were skeptics: “That is not true, there were no text messages; I had four working cellphones in my Chelyabinsk apartment—after the explosions, all of them stopped working,” wrote a user named Yegor on the kp.ru website. “I saw the phenomenon with my own eyes, and I do not believe in meteorite version, it looked more like a burning airplane,” another person wrote.

Photographs on social networks and YouTube videos published by witnesses showed pieces of a shopping center falling off on Truda Street, pieces of the destroyed roof of a local zinc factory, and crowds of people running in panic. The key word causing the fear? Radiation. Chelyabinsk, a city with 1.1 million people across the Ural Mountains from Moscow, is a center for nuclear facilities and the military industry.

Emergency services called on people to save water and food tonight. The meteor interrupted life at least in the western part of the city, and reports cautioned people not to touch the meteor if they come across any pieces. Some industrious Chelyabinsk citizen has already offered to sell a piece of the meteor for a souvenir. “I found it earlier today, I will publish the photograph later,” promised the entrepreneur online. Earlier today women waiting for a train in the Moscow subway discussed the events, seemingly worried about the reports of an (unrelated) asteroid making a close fly-by to Earth in the coming 24 hours.

As if to add gasoline to the fire, Vladimir Zhirinovsky, the leader of the Russian Liberal-Democratic Party, said that it was not a meteor exploding in Chelyabinsk, but a new weapon of mass destruction being tested by United States, saying: “John Kerry tried to warn the Russian foreign minister on Monday about the upcoming provocative tests that would concern Russia, but [Foreign Minister] Lavrov was away. ” The idea had a short but powerful resonance: why did the meteor explode above ground, people wondered? Astrophysicists say it was a bolide, or a meteor that explodes in the air. Speculations and conspiracy theories bounced from Russian cafés to taxis for at least a couple hours.

Russian environmentalists remain concerned about the situation in Chelyabinsk, a region where Russia has for years buried thousands of tons of radioactive waste. Mayak, a nuclear facility, has several nuclear reactors and is a storage site for radioactive waste.

Vladimir Chuprov, the head of the energy program at Greenpeace Russia, explained on Dozhd TV what would happen if Mayak were hit: “There is storage for several dozen tons of plutonium; in case the storage becomes insecure, it would mean that Russia would lose the entire Ural region.”