The mystery deepened Thursday into what happened to a student pilot and his flight instructor after their single-engine Cessna 172 airplane disappeared over the coast of Catalina Island on a flight to Van Nuys Airport on Saturday.

The U.S. Coast Guard Search suspended its search at 8 p.m. Monday after more than 16 hours of searching, according to U.S. Coast Guard Petty Officer Third Class Loumania Stewart.

Stewart said the search could be resumed if there was any sign of evidence of the airplane’s possible whereabouts, but as of early Thursday afternoon the search remained suspended.

The Coast Guard was notified about 5:30 a.m. Monday that the plane had gone missing, Stewart said.

“An HC-130 aircrew from Coast Guard Air Station Sacramento and an MH-65 aircrew from Forward Operating Base Pt. Mugu were launched,” she said

“Based on information passed to the Coast Guard, crews saturated their search efforts around the island of Catalina spanning more than 1,400 square miles for the Cessna-type aircraft and its crew.”

With no signs of any aircraft or anyone in distress, the search was suspended, she said.

According to the Los Angeles Times, the two people aboard the aircraft were student pilot Edmond Haronian, 50, of Woodland Hills, and his instructor, Jason Glazier, 52, of Encino.

Haronian was taking flying lessons for about a year at the Van Nuys- based Encore Flight Academy.