Huge explosions in a warehouse district sent up massive fireballs thatturned the night sky into day, killing at least 44 people and injuringhundreds in the Chinese port city of Tianjin, officials and witnessessaid Thursday.Twelve of the dead were from among the more than 1,000 firefighters sent to fight the blaze set off by the explosions shortly before midnight, the Tianjin municipal government said. It said 520 people were being treated in hospitals, 66 of them with serious injuries. It gave no figure for the missing.The blasts, originating at a warehouse for hazardous material, turned buildings in the immediate vicinity into charred, skeletal shells while shattering windows up to several kilometers (miles) away.”I thought it was an earthquake, so I rushed downstairs without my shoes on,” said Tianjin resident Zhang Siyu, whose home is several kilometers from the blast site. “Only once I was outside did I realize it was an explosion. There was the huge fireball in the sky with thick clouds. Everybody could see it.”Zhang said she could see wounded people weeping. She said she did not see anyone who had been killed, but “I could feel death.”There was no indication of what caused the blasts, and no immediate…