Moscow (CNN)More than 1 million historic documents have been destroyed in a fire at one of Russia's largest public libraries, according to the Russian state news agency Tass.

The Russian emergency situations ministry says 147 firefighters struggled for 25 hours over the weekend to put out the blaze in the main library of the Institute for Research Information on Social Sciences in Moscow.

The fire, which ripped through the library Friday evening, destroyed 2,000 square meters (about 2,400 square yards) of the building and caused part of the roof to collapse, according to an official statement. The Russian emergency situations ministry said the fire was particularly hard to put out because of the high temperatures, narrow passageways and the risk of the building falling down.

Moscow's emergency ministry said the temperature inside the rubble of the library remains high and that there is still a threat that the building could collapse.

Vladimir Fortov, president of the Russian Academy of Sciences, told the Russian news agency RIA Novosti that the fire, which destroyed 15% of all the documents in the library, reminded him of the 1986 disaster at the Chernobyl nuclear plant in Ukraine.

"It's a major loss for science. This is the largest collection of its kind in the world, probably equivalent to the Library of Congress," Fortov told the agency. "It contains material that you can't find anywhere else and all the social science institutions use this library. What has happened here is reminiscent of Chernobyl."

The institute's director, Yuri Pivovarov, told Tass that he fears the building cannot be restored.

Based on the article and the following list of answers, write a list of questions.

1. yes
2. 147
3. 25 hours
4. president of the Russian Academy of Sciences
5. high temperatures, narrow passageways and the risk of the building falling down
6. Chernobyl
7. 1986
8. no
9. 140000
10. Ukraine

Numbered questions:
1. Did the firefighters struggle?
2. How many were there?
3. How long did they work on putting it out?
4. Who is Vladimir Fortov?
5. Why was it so hard to extinguish?
6. What other major disaster is this event being compared to?
7. When did that happen?
8. Can the building be fixed?
9. How big was the library?
10. Where was chernobyl located?