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.  QUESTIONS:

Q1:
1. Did the firefighters have a hard time?
2. Was it difficult for firefighters to put out the blaze?
3. Did firefighters struggle to put out the fire?
Q2:
1. How many firefighters were there?
2. What was the number of firefighters present?
3. What quantity of firefighters was needed?
Q3:
1. How long did it take firefighters to put out the blaze?
2. How long did firefighters spend extinguishing the fire?
3. How many hours were needed for firefighters to extinguish the blaze?
Q4:
1. What is Vladimir Fortov's title?
2. What does Vladimir Fortov do?
3. What position is held by Vladimir Fortov?
Q5:
1. Why was it so hard to put out the fire?
2. Why was the blaze so difficult to extinguish?
3. What made the fire so tough to put out?
Q6:
1. What other major disaster is the fire being compared to?
2. What other devastating event is being compared to the fire?
3. What comparison is being made between the fire and another disastrous event?
Q7:
1. When did Chernobyl happen?
2. In what year did Chernobyl occur?
3. What was the year of the Chernobyl disaster?
Q8:
1. Can the library be repaired?
2. Is it possible to fix the Russian library?
3. Can repairs be made to the library?
Q9:
1. What was the size of the library?
2. What was the Russian library's size?
3. How big was the the main library of the Institute for Research Information on Social Sciences in Moscow?
Q10:
1. What country was Chernobyl in?
2. In what country could Chernobyl be found?
3. Which nation was home to Chernobyl?
