The second "Clear Creek Courant" article covers the #21's breakdown. I'll quote two sentences from this article:
Railstar did report in January that budget shortfalls for winter caused delays in some maintenance on the engines.
In the annual report to the Colorado Historical Society, Railstar noted that “the winter budget had to be trimmed so tight that we believe it will impact the ability to complete the necessary maintenance so that equipment is ready by the start of the season. This will call into question the reliability of the locomotive #12 throughout the season and the ability to have enough cars ready in time to meet peak season demand.”
--
Chris Webster
[www.speakeasy.org]