NAPA (KRON) — Construction to replace the earthquake damaged Oakville Crossroad Bridge in Napa County begins Monday.

The bridge which crossed over the Napa River between Highway 29 and Silverado Trail was closed following the May 21st quake near Yountville. County officials say the 4.1 magnitude quake caused the base that held up the west end of the bridge to sink four inches. That led to existing cracks on the nearly 100-year-old span to be pulled apart, exposing structural steel and creating unsafe conditions, according to officials.

Crews completed the demolition of the bridge over the past several weeks.

The bridge was already scheduled for replacement due to its age and deteriorated condition.

But the quake forced the early closure of the span. The Napa County Public Works has been closely consulting with contractors and regulatory agencies, and has been in communication with the project’s funding partners (Caltrans and the Federal Highway Administration) to accelerate the project from a two-year phased reconstruction to one that can be completed in only seven months, officials said. The goal is to have a two-lane replacement span by January 1st.

The county says that while the revised plan is achievable, they face many challenges. Bridge materials that were ordered for delivery over a two-year period now need to be manufactured and delivered in a matter of months. Many endangered species are known to inhabit the area, so environmental concerns could slow down the project. Bad weather could also stall construction.