Transcript for The Mystery of the Warehouse Explosion in China
Overseas and China now and the search for survivors after two deadly explosions. Two more today. And one man pulled out today in this stunning footage from an American man capturing the blinding terror. As we now know, the explosion felt for miles. And ABC's bob woodruff on the mystery how it erupted in the first place. He's on the scene in China. Oh, my god! Reporter: Tonight the man who shot those powerful images taking us upstairs over shattered glass to the roof where he witnessed it all. The whole sky turned yellow. Reporter: One explosion after another. Then the sky turned white. Second later, an enormous blast. Let's go down! I thought it looked like a nuclear bomb going off in my face and it felt like that. I mean it blew us back. Reporter: But this morning in the charred landscape, a 19-year-old firefighter found alive. Today, new blasts at the chemical storage facility. Chinese officials say they still don't know which hazardous materials were kept there or whether the firefighters spraying water on the toxic blaze may have accidentally triggered Wednesday's explosions. Now, even though investigators wear gas masks, the government insists the air is safe to breathe. Many residents here aren't taking any chances. Now, the government is starting to close down social media accounts we have been following on our phone, accusing them of spreading rumors and causing panic. However, even reports from credible news sources are being censored more and more every day. David? Bob woodruff from China tonight.
This transcript has been automatically generated and may not be 100% accurate.