Construction has begun on the damaged Oroville Dam, and workers used controlled blasts to demolish portions of the bottom of the spillway on April 24.

Officials told the San Jose Mercury News because water flows had stopped for the season, contractors were able to begin with the controlled explosions for demolition.

Damage caused by erosion was discovered on the spillway in February as heavy rainfall drove up the level of Lake Oroville. The town below the dam was evacuated in case of a breach. People were allowed home within days. Officials have been working to repair the spillway since.

This video, showing different angles from the blasts, was shared by the California Department of Water Resources.