Joe Martinez and his fellow riders on a BART subway train feel a sudden violent motion in the earth. The train stops quickly, and everyone assumes that San Francisco has been struck by a strong earthquake. Following the emergency instructions posted in the train, Joe walks inside the tunnel toward the nearest exit at the Montgomery Street station, about a mile from Ground Zero—the point where the terrorists detonated the nuclear explosive. The passengers are not surprised to find that the power is out and the escalator to the exit doesn't work, but as they emerge from the darkened, deserted station onto Market Street, they see a scene worse than any they have ever imagined.
San Francisco's financial district has become a field of flames and rubble. Not a structure is standing from Montgomery Street to the bay, and the hotels and department stores on Union Square appear on the point of collapse. Moscone Center has been leveled. The sky above is filled with a hot, stifling mist that does nothing to extinguish the burning remains of buildings, vehicles, and human beings. A wall of steam rises from what used to be the Embarcadero Promenade, preventing Joe from seeing the lip of a crater filled with boiling water. Joe also can't see that the Bay Bridge between the City and Yerba Buena Island has vanished, vaporized or fallen into the bay along with thousands of cars and trucks.
Most people whom Joe can see have burned to death. A few survivors cry out from the pain of third-degree burns and burning clothing. The heat is so intense that Joe's first instinct is to retreat back into the underground station. This instinct will save his life—underground, he will be protected from the radioactive fallout that will soon begin settling on what used to be San Francisco. Before taking shelter inside the BART station, Joe takes out his cell phone and tries to call his wife Kathleen. She doesn't answer, and as Joe looks northwest toward Nob Hill, he understands why, and his heart sinks.