Alameda County deputies on Wednesday evening responded to a report of a small plane going down near Interstate 580 in Castro Valley that turned out to be unfounded, according to the Sheriff's Office.
A motorist traveling on I-580 said they saw a small plane in distress go down in the hills near 580 and Rowell Ranch, sheriff's officals said.
However, an air and ground search revealed no crash site, officials said, and they later learned it may have been an experimental aircraft that landed in the hills and took off again.
Sheriff's deputies made contact with the experimental pilot and concluded the crash was unfounded.
Deputies searched on foot, helicopters searched from above and fire crews also responded to the search scene, sheriff's officals said.