But while personnel at the Jefferson County Sheriff's Office can't say precisely what happened to spur the accident, they're confident at this point that nothing criminal took place.
According to JCSO public-information officer Mark Techmeyer, two agencies were initially charged with looking into the incident: the sheriff's office and the Colorado Department of Labor and Employment, whose public safety section monitors explosives, carnival rides and amusement-park permits.
"We conducted the preliminary investigation," Techmeyer says, "and we found nothing that leads us to believe or suspect that anything criminal could have led to this accident. We're keeping the case open in case the Department of Labor needs assistance down the road. But they're going to be handling the investigation now."
In the meantime, Techmeyer updates the injury situation. "It's my understanding that 21 people were assessed at the scene, and five of those people refused transport -- but sixteen people were transported and seen at the hospital." Most, but not all, of them have since been released; Techmeyer says that as of this morning, two were still hospitalized.
Look below to see first-day coverage from Channel 9, plus photos of the trains from the Tiny Town website: