UPDATE: At 4 a.m. on Sept. 12 the road reopened.
BOULDER COUNTY, Colo. (CBS4) – A major rockfall forced CO 119 in Boulder Canyon to close on Wednesday. The Colorado Department of Transportation says the rockfall came from a previously scheduled blast.
That blast was part of the CO 119 flood construction project which will move the roadway onto more bedrock to prevent possible erosion during a major flood.
Crews say a typical blast sends about 400 cubic yards of rock down the canyon, but this blast caused about 8,000 cubic yards of rock to fall onto the road.
For reference, officials say a cubic yard is about the size of a washing machine.
No one was hurt.
Some of the boulders were too big to move and will needed to be blasted themselves. Additionally, the blast caused other rock to be loosened.
Officials with the Boulder Valley School District said they would send school buses to homes on the other side of the blast. Highway 72 is being used as a detour.