Operation Crossroads was a huge event, described as “the apocalypse with fireworks.” To someone who didn’t know World War II was over, the scene on the lagoon at Bikini that day might have seemed surreal. An armada of captured German and Japanese warships had been lined up alongside retired American cruisers and destroyers. These were massive, football-field-size warships whose individual might was dwarfed only by the combined power of them all. Eight submarines had been tethered to anchors on the ocean floor. There were over one million tons of battle-weary steel floating on the ocean without a single human on board. Instead, thousands of pigs, sheep, and rats had been set out in the South Pacific sunshine, in cages or in leg irons, and they would face the coming atomic blast. Some of the animals had metal tags around their necks; others had Geiger counters clipped to their ears. The Navy wanted to determine how living things fared against nuclear bombs.
Forty miles west of the lagoon, Alfred O’Donnell stood below deck in the control room of an observation ship watching the control bay. Above him, on deck, Los Alamos scientists, generals, admirals, and dignitaries waited in great anticipation for the bomb. Shielding their eyes were dark, 4.5-density goggles, necessary measures to prevent anyone from being blinded by the nuclear flash. O’Donnell worked the instrument panel in front of him. There were sixty seconds to go. He watched the auto sequence timer perform its function. With less than a minute remaining, the firing system moved into automation. The bars on the oscilloscopes moved from left to right as the signals passed down through the DN-11 relay system. There were ten seconds left. Then five seconds. The light for the arming signal blinked on. Two seconds. The firing signal flashed.
It was zero time.
O’Donnell kept his eyes on the control panel down to the last second, as was his job. In the event of a malfunction, it would be up to him to let the commander know. But the signal had been sent without a problem, and now it was moving down the underwater wires, racing toward the Baker bomb. If O’Donnell moved fast, he could make it onto the ship’s deck in time to see the nuclear blast. Racing out of the control room, he pulled his goggles over his eyes. Up on the ship’s deck he took a deep breath of sea air. There was nothing to see. The world in front of him was pitch-black viewed through the goggles. He stared into the blackness; it was quiet and still. He could have heard a pin drop. He listened to people breathing in the silence. Facing the lagoon, O’Donnell let go of the ship’s railing and walked out farther on the deck. He knew the distance from the button to the bomb and the time it took for the signal to get there. In a matter of seconds, the signal would reach its destination.
There was a blinding flash and things were not black anymore. Then there was a white-orange light that seemed brighter than the sun as the world in front of O’Donnell transformed again, this time to a fiery red. He watched a massive, megaton column of water rise up out of the lagoon. The mushroom cloud began to form. “Monstrous! Terrifying! It kept getting bigger and bigger,” O’Donnell recalls. “It was huge. The cloud. The mushroom cap. Like watching huge petals unfold on a giant flower. Up and out, the petals curled around and came back down under the bottom of the cap of the mushroom cloud.” Next came the wind. O’Donnell says, “I watched the column as it started to bend. My eyes went back to the top of the mushroom cloud where ice was starting to form. The ice fell off and started to float down. Then it all disappeared into the fireball. Watching your first nuclear bomb go off is not something you ever forget.”
Mesmerized by the Baker bomb’s power, O’Donnell stood staring out over the sea from the ship’s deck. He was so overwhelmed by what he’d witnessed, he forgot all about the shock blast that would come his way next. The wave of a nuclear bomb travels at approximately one hundred miles per hour, which means it would reach the ship four minutes after the initial blast. “I forgot to hold on to the rail,” O’Donnell explains. “When the shock wave came it picked me up and threw me ten feet back against the bulkhead.” Lying on the ship’s deck, his body badly bruised, O’Donnell thought to himself: You damn fool! You had been forewarned.