the wrong place… i just need help understanding the theme?

“The Wrong Place” by Susan MichalskiLana woke up, curled in a corner of the seat at the back of the train. She lifted the shade to see that the sun had hidden itself in a bank of clouds fluffy as the eiderdown her mother had wrapped her in as a child. Her darling Ted, a military man with a distinguished career, had gone to Philadelphia on some urgent business. Before he left, she knitted him a red cap and scarf to keep him warm. Finally, when she could wait no longer, she too packed a bag and boarded the northbound train. The low and constant rumble under her feet lulled her into a daydream. She closed her eyes and stretched out beside her husband on their big white bed. The heat of his body warmed her, and she laughed at the rumbling of his snores.A violent jolt threw Lana to the car floor and brought her back to the moment. Seconds later, the deafening grind of steel on steel tore through the train. Bags and people tumbled like mad acrobats all around her, but Lana remained wedged under her seat. When the movement ceased, all that remained was an endless sea of sound. Screaming, pounding, hissing noises assaulted Lana from all sides. In desperation she pushed her way free from the mangled seat and clawed her way out.The train lay in pieces, scattered about like a toy tossed by a petulant child. An entourage of uniformed men prowled around the wreckage. Lana grabbed the arm of one as he hurried past, “What… ?” She couldn’t form the words to ask. “A bomb, Miss, the President was on the train —.” The man’s voice trailed off as he continued his explanation. Across the expanse of the field, a man on horseback darted in and out of the trees heading toward a road on the other side of the trestle that the train had somehow cleared despite the explosion. A flash of red caught Lana’s eye. She raced toward it, leaving the guard in mid-sentence. She closed the distance surprisingly quickly because of the hill and her angle of descent, but she was no match for the horse who made it to the trestle in time for a second fireball to fill the sky. Wood and metal rained down on the rider. Lana fell to the ground and covered her head waiting for the earth to be still. Finally, she crawled to where a red scarf that had flown from the neck of the horseman lay a few yards away. She inhaled the scent and wept. “Oh, my Teddy! I am so sorry! Whatever were you doing here?”What is the theme?