How do you explain the shadows that happened at ground zero?

https://www.livescience.com/nuclear-bomb-wwii-shadows.html

Can someone actually show me shadows made from non nuclear explosions? Doesnt sound like its possible, but i could always be wrong.

The intense energy released during an atomic explosion is the result of nuclear fission. According to the Atomic Heritage Foundation, a nonprofit based in Washington, D.C., fission occurs when a neutron strikes the nucleus of a heavy atom, like the isotopes uranium 235 or plutonium 239. (An isotope is an element with varying numbers of neutrons in its nucleus.) During the collision, the element's nucleus is broken apart, releasing a large amount of energy. The initial collision sets off a chain reaction that continues until all of the parent material is exhausted.

"The chain reaction occurs in a pattern of exponential growth that last[s] a millisecond or so," said Alex Wellerstein, an assistant professor of science and technology studies at the Stevens Institute of Technology in New Jersey. "This reaction splits about a trillion, trillion atoms in that period of time before the reaction stop[s]."

The atomic weapons used in the 1945 attacks were fueled by uranium 235 and plutonium 239 and released a massive amount of heat and very shortwave, gamma radiation.

Energy flows as photon waves of varying lengths, including in long waves, like radio waves, and in shortwaves, like X-rays and gamma-rays. Between long waves and shortwaves lie visible wavelengths that contain energy that our eyes perceive as colors. However, unlike energy with longer waves, gamma radiation is destructive to the human body because it can pass through clothing and skin, causing ionizations, or the loss of electrons, that damage tissue and DNA, according to Columbia University.

The gamma radiation released by the atomic bombs also traveled as thermal energy that could reach 10,000 degrees Fahrenheit (5,538 degrees Celsius), Real Clear Science reported. When the energy hit an object, like a bicycle or a person, the energy was absorbed, shielding objects in the path and creating a bleaching effect outside the shadow.