Skyhawk 172/Cutlass 172
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 1
Situational Awareness
ATC Issue All Types; Aircraft Equipment Problem Critical; Ground Event / Encounter Gear Up Landing
Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition
Aircraft
Aircraft X departed VFR. Shortly after take-off the pilot advised local of a gear malfunction/issue. Aircraft X performed a low approach over the runway and we observed the pilot side of the gear retracted while the co-pilot gear appeared down.  Aircraft X circled the airspace for a few minutes until the fire brigade arrived at the airport. Aircraft X landed and came to a stop/disabled at [runways] intersection. No injuries; unknown damage; pilot was sole occupant; 3 hours of fuel.  I contacted one of the airport's FBO who dispatched a crew to assist the aircraft. My shift ended prior to the aircraft being removed from the Runway.Everything went smooth except for the phone calls from the Service desk.
Aircraft landed with left main gear retracted. This was a known malfunction.