Dhaka, Aug. 7 -- As black smoke billowed into the sky, Shiva Karout stepped out of his gym with his colleagues and customers to watch. His gym, Barbell House, sits just across the coastal highway from Beirut's port where a fire raged. They were curious.

Then a first boom shook them, and curiosity turned to fear realizing how close they were. "We got a bit scared, and we all went back in," Karout recounted. Tense moments passed, waiting inside, and one of his customers panicked and ran out. Karout went after him.

That was when hell erupted. A gigantic explosion threw up a towering mushroom cloud and sucked out the air, and a wave of destructive energy shot across Lebanon's capital.

The force threw Karout to the ground. He was cut and br...