The roof of the water park collapsed on February 14, killing 26 people and injuring more than 100.
A source close to the investigation told RIA Novosti, "experts have not found any particles of an explosive on the samples taken at the scene of the tragedy. So, on the basis of the expert examination's data it is safe to say that the destruction of a load bearing column of the water park's roof was of a technical nature."
According to the source, the first results of the explosive-technical expert examination, carried out at a Moscow scientific research institute, do not point to an act of terrorism.
The deputy chairman of the Russian Federation's State Construction Committee, Larisa Barinova, told journalists in Moscow the committee does not have any data that an act of terrorism was perpetrated at Transvaal park. "For now, we have no data to say whether there was a terrorist act or not," she said.
Ms. Barinova said that the State Construction Committee can now say what actually happened at the water park based on films taken inside the park. "Something happened to a column," she said. "A small cloud appeared near one of the columns before it 'fired.' The span between the columns is six meters long. After the first column collapsed, all of the other columns opened like in a fan. The third sequence of the footage shows the roof falling."
Moscow Mayor Yuri Luzhkov has ruled out the act of terrorism version.
He said, "the causes are not external but internal and linked to architecture, planning and construction."
Deputy Prosecutor of Moscow Vladimir Yudin also refuted the reports in the media that the Moscow water park tragedy was an act of terrorism. "We have no data to this effect. The investigation does not have such information," Mr. Yudin said.
"As before, we are not considering the terrorist attack version but we will examine the structures in order to remove all the suspicions and to prevent speculations," Mr. Yudin.
The Moscow Prosecutor's Office launched a criminal case on the fall of the roof and the death of people in the water park under Part II of Article 109 (causing death through negligence) of the Russian Federation's Criminal Code.