 What caused the explosion that resulted in the loss of air on Freedom 19?
General Finogenov notified Major Winship that the underground blast was scheduled for the following morning. Next morning, before the sunlight exploded, the four of them donned their space suits and went and sat outside the dome, waiting. "I'll try again," Major Winship said and switched to the emergency channel. His foot was lifted for the second step when the floor beneath him rose and fell gently, pitching him forward, off balance. Air currents whisked it away and plastered it against a riveted seam of the dome. It pulsed as though it were breathing and then it ruptured. Major Winship moved quickly to cut out the emergency air supply which had cut in automatically with the pressure drop.
 The calking mixture leaked onto the air tank.
 The room became too hot from overcrowding  The calking mixture leaked onto the air tank.  The compound mixture became too hot because of the lack of the air reconditioner  The compound mixture was mixed too quickly.