After Seafloor Systems workers found an airplane in one of Folsom Lake's deepest points last week, California authorities immediately investigate the mystery plane.

The workers thought the plane might be the missing Piper Comanche 250 airplane that crashed in the California lake in 1965. However, the Placer County Sheriff's Office said on Wednesday, June 16, that the mystery plane was from a 1986 non-fatal crash.

1986 Crash: A Non-fatal One

The 1965 crash killed the pilot and three passengers who were on board on New Year's Day. Three bodies inside the Piper Comanche remain missing in a California lake since only the pilot's body had been recovered, according to The Guardian.

Searchers hoped that underwater surveyors had found the remains of over half a century's wreckage which will solve the mystery. However, the discovered plane was that of a 1986 crash with no fatalities reported. The sheriff's office decided that the plane will remain at the bottom of the lake.

A dive team alongside the Placer and El Dorado county sheriffs' offices went back to Folsom Lake together with the Seafloor Systems technicians to take more detailed images of the wreckage on Tuesday, June 15. 

During their search for more clues, they have proved that the initial assumption was wrong, KCRA reported.

READ NEXT: California Gov. Gavin Newsom Declares State of Emergency Amid Heat Wave

The 1965 Crash in California Lake

The staff of the company Seafloor Systems was testing its underwater survey equipment last week when it spotted what appeared to be a small airplane 160 feet underwater.

Based on their initial assessment, they suspected that it might be the missing Piper Comanche, but they could not confirm any aircraft number.

The current historic drought that California is experiencing made a perfect condition for exploration on the lowest depths of Folsom Lake, which is a reservoir of the American River. California's historic drought put the water levels extremely low, just over a third of its usual storage capacity.

The search was not the first instance of attempting to uncover the 1965 crash while the authorities took advantage of the dry season. 

In 2014, during another major drought, dive teams and a couple with a sonar boat came up empty looking for the plane that was missing already for more than five decades.

Instead of easily locating the wreckage, divers during the 2014 search found themselves in a tough spot as the lake's low water levels made the water fuzzy, which made the search complicated.

These searches would be the last if the victims' families from the 1965 plane crash have their wishes respected.

According to the Placer County Sheriff's Office, the victims' relatives asked for searches for the plane and the bodies to stop.

The sheriff's office noted that the victims' families would like the final resting place for their loved ones to remain at the bottom of Folsom Lake, San Francisco Chronicle reported.

READ MORE: California Drought May Have Solved Mystery of 50-Year-Old Plane Crash; Remains Discovered by Underwater Surveying Company

WATCH: Airplane Debris Discovered in California Lake Not From Doomed 1965 Crash - From Vanguard News