Forty-seven people died in the crash and more than 125 people were injured. However, as the WikiWackyWoo puts it, "Following this disaster, advancements in train speed in the United States essentially halted."
According to the Exposition Flyer's crew engineer, W.W. Blaine applied the brakes immediately upon seeing the warning signals, but the stopping distance was greater than they had. When it plowed into the rear coach of the train it was still traveling at 60 miles an hour. It jumped up and its momentum cleaved the roof of the Advance Flyer's last coach and buckled the diner car, the second from the end. In all 11 cars on both trains derailed, throwing people in every direction.
Adam Doster in The Crash that Rocked Naperville:
Dust, smoke, and debris scattered across the nearby countryside. The smell of ashes hung in the air. “The scene of the disaster,” the Tribune noted later that day, “was one of twisted and gnarled confusion, with huge luxury passenger coaches strewn across torn tracks like abandoned toy trains.” For a few seconds after the collision, the passengers on board made little noise. Then the shock wore off. “A moment of tragic silence was broken,” the AP wrote, “by screams and cries for help from the dying and injured.” The rear of The Advanced Flyer absorbed the bulk of the damage—most of those sitting in the rear coach and diner car were killed straightaway. Those seated further up the train escaped the worst, but were rocked nonetheless. “Things happened so fast,” one passenger said, “that I don’t remember what happened to me. I was doubled up suddenly and my knees were pushed against my chest.”
W.W. Blaine was exonerated of the manslaughter charge that followed the crash. One lasting result of the Interstate Commerce Commission hearings was the mandate that only trains with automatic train stop devices could exceed 79 miles per hour. Since this federal law was instituted in 1951 few passenger trains have installed the devices, keeping most passenger rail speeds below the 79 MPH threshold.
And, that's why April 26, 1946 is the day that effectively killed high speed rail in 'Merka - 67 years ago today!