The Tiny Town train derailment occurred when a train engineer reached for a brake lever, but mistakenly pulled the accelerator lever as the train hit a sharp curve, state investigators said Thursday.Twenty people, including several children, were hurt Wednesday morning when the small open-car train tipped onto its side, tossing passengers out of their bench-style seats.The train engineer, described as a man in his 40s, freely acknowledged the mistake in an interview with an investigator from the Colorado Department of Labor and Employment, which regulates amusement park rides, said agency spokesman Bill Thoennes."At this point, all indicators are that it was due to operator error," Thoennes said.The man told the investigator that the train was going too fast as it was approaching a sharp turn, so he yanked what he thought was the brake lever."He discovered that he was accelerating too fast -- unfortunately, just as he was about to hit a 90-degree turn," Thoennes said. "He quickly reached to brake and he accidentally pulled the wrong lever and accelerated instead of braking. Hitting the acceleration caused it to move rapidly forward and then hitting that turn as it did, it tipped over some of the cars."Rex Thrash, a 36-year veteran of the Colorado Railroad Museum said steam engines are equipped with throttles, not accelerators. Thrash said the Tiny Town engineer likely set the train brake but failed to shut the throttle, which would have stopped the train by cutting off steam to the engine's drivers."[According to witnesses] the wheels were still turning, which told me the throttle was still partially open," said Thrash.The engineer, who may be a volunteer, has worked two summers at the amusement park and driven that specific engine 30 times, Thoennes said. He gave investigators a statement saying he "accepts responsibility" for the accident, Thoennes said."He's a very passionate individual when it comes to trains," Thoennes said.The derailment occurred at about 10:45 a.m. Wednesday. Of the 20 people who were hurt, 16 were sent to four local hospitals with injuries ranging from cuts and bruises to broken bones. Two adults and one child who had the most serious injuries were taken to Swedish Hospital.By Thursday, one person remained hospitalized in fair condition.The 95-year-old amusement park with more than 100 colorful kid-sized buildings closed after the accident. It is expected to reopen on Friday, although the train rides will be shut down until next Wednesday.Thoennes said any possible sanctions from the incident would be against Tiny Town and not the engineer. He said penalties could range from fines to forcing the train ride to close until owners prove it can operate safely.Jefferson County Sheriff's Department spokesman Mark Techmeyer said its investigation concluded that the there is no criminal liability for the engineer.Ken Haraldsen, a former volunteer train engineer at Tiny Town, said he could tell what happened when he saw TV helicopter news coverage of the narrow-gauge steam engine derailed at the curve."I said, 'Oh, oh, they were going too fast,' " Haraldsen, 87, recalled."See the tracks are narrow and with a lot of people on the train it sort of makes it top-heavy when you go around a turn," he said.I wouldn't go over 5 miles an hour," Haraldsen said. "It was just comment sense, knowing what happens on curve if you go too fast."Haraldsen said volunteer engineers learned to gauge speed by instinct and experience, because the engines lack speedometers.He said only the most experienced engineers operated the larger Engine 10 that crashed, because the steam-engine was more complicated than park's two gasoline and one propane-gas engines.