Two engineers working on First Solar's Desert Sunlight Solar Farm were killed yesterday when their plane crashed near the construction site close to Joshua Tree National Park.

Mike Cyr and Jeff Randall, civil supervisors at the project, were flying in a single-engine 1971 Model AA-1A fixed wing aircraft over the project about 1:30pm on Monday when it crashed. Both of the men were direct First Solar employees. A Colorado River Station sheriff’s deputy and a Bureau of Land Management ranger who were patrolling the area saw the crash.

Jim Hughes, chief executive of First Solar said: “The First Solar community was deeply saddened to learn of the deaths of two associates in an accident near the Desert Sunlight Solar Project Monday afternoon.

“We extend our deepest condolences to Mike and Jeff’s families and loved ones. We are in contact with the families, and are providing our support in this difficult time.”

The accident is under investigation by the National Transportation Safety Board and First Solar is cooperating fully with authorities, he added.

First Solar is currently constructing the 550MW Desert Sunlight Solar Farm in Riverside County, California, which is co-owned by NextEra Energy Resources, GE Energy Financial Services, and Sumitomo Corporation of America. The project is located on land managed by the Federal Bureau of Land Management (BLM), about six miles north of the community of Desert Centre.

Construction began in September 2011, and the facility is expected to be fully operational by 2015 with power purchase agreements with Southern California Edison and Pacific Gas & Electric.

Local reports said that the area where the solar facility is located was hit by storms and floods from Tropical Storm Ivo at the weekend which washed out roads and caused power outages. The airplane may have been used to survey potential damage, the reports suggested.