Hayward Baker won a roughly USD 830,000 contract to do repairs. The repair project started earlier this week.
The hole opened 9 July 2012 when the soil gave way above the abandoned, partially-collapsed railroad tunnel, which has been disused since the 1950s. Colorado Department of Transportation thought the tunnel had settled and built over it many years ago.
The collapsed tunnel was the first tunnel built under Tennessee Pass. Union Pacific replaced the tunnel with another one about 550m away. The replacement tunnel is still in use and was not damaged in the collapse.
