LAS ANIMAS COUNTY, COLO. -- A bridge on Highway 12 west of Trinidad collapsed Wednesday, forcing crews to build an alternate route before the weekend.

According to Colorado Department of Transportation officials, Highway 12 was closed about a mile west of Weston, Colo. after a two-foot section of the Purgatoire River Bridge fell through.

Crews closed the Highway after noticing a crack on the deck of the bridge, though most of the existing bridge remains intact.

No people or cars were on or under the bridge when it broke off.

Crews are constructing a detour parallel to the bridge. They are in the process of placing culverts and paving the road for travel and hope to have it open by Friday afternoon.

The current bridge, which was built in 1925, was in the process of being replaced, so eastbound and westbound traffic were alternating using the one open lane. The bridge will be closed to traffic until all replacements are complete. In the meantime, cars can use the detour beginning Friday afternoon.

From Trinidad, cars can still drive Highway 12 as far west as Weston.  All other traffic heading to points west of Weston are being directed to U.S. 160 through Walsenburg, west on U.S. 160 to Highway 12, and south on Highway 12 through La Veta.

Click here for the latest statewide road closures.