What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Incident happened at komn on runway 17. Winds were 170@10 as aircraft returned back into Ormond, tower cleared them for the straight in runway 17 report 4NM straight in. They reported the 4NM final straight in and waited until 3NM to complete their first gumps checklist. Power went 15? And deployed gear. They confirmed 3 green no red one in the mirror and continued gumps/pre-landing checklist.
At approximately the 2NM mark the student completed another gumps check and verify 3 green no red one in the mirror.
Short final they checked once again for gear down and confirmed all green were lit with no gear warning horn.
Student leveled the PA34 in ground effect and had a centerline smooth landing, no CFI assistance needed. We began rolling out on the runway when suddenly the left side of the aircraft collapsed. Instructor promptly pulled the mixture to cut-off before nose came down. They began sliding to the left side of the runway towards the grass and runway lights, which then felt as if we were solely sliding on the belly of the plane. I turned everything off, notified ATC and had the student and I exit the aircraft.
As the FAA filed it
INCIDENT HAPPENED AT KOMN ON RUNWAY 17. WINDS WERE 170@10 AS AIRCRAFT RETURNED BACK INTO ORMOND, TOWER CLEARED THEM FOR THE STRAIGHT IN RUNWAY 17 REPORT 4NM STRAIGHT IN. THEY REPORTED THE 4NM FINAL STRAIGHT IN AND WAITED UNTIL 3NM TO COMPLETE THEIR FIRST GUMPS CHECKLIST. POWER WENT 15? AND DEPLOYED GEAR. THEY CONFIRMED 3 GREEN NO RED ONE IN THE MIRROR AND CONTINUED GUMPS/PRE-LANDING CHECKLIST.
AT APPROXIMATELY THE 2NM MARK THE STUDENT COMPLETED ANOTHER GUMPS CHECK AND VERIFY 3 GREEN NO RED ONE IN THE MIRROR.
SHORT FINAL THEY CHECKED ONCE AGAIN FOR GEAR DOWN AND CONFIRMED ALL GREEN WERE LIT WITH NO GEAR WARNING HORN.
STUDENT LEVELED THE PA34 IN GROUND EFFECT AND HAD A CENTERLINE SMOOTH LANDING, NO CFI ASSISTANCE NEEDED. WE BEGAN ROLLING OUT ON THE RUNWAY WHEN SUDDENLY THE LEFT SIDE OF THE AIRCRAFT COLLAPSED. INSTRUCTOR PROMPTLY PULLED THE MIXTURE TO CUT-OFF BEFORE NOSE CAME DOWN. THEY BEGAN SLIDING TO THE LEFT SIDE OF THE RUNWAY TOWARDS THE GRASS AND RUNWAY LIGHTS, WHICH THEN FELT AS IF WE WERE SOLELY SLIDING ON THE BELLY OF THE PLANE. I TURNED EVERYTHING OFF, NOTIFIED ATC AND HAD THE STUDENT AND I EXIT THE AIRCRAFT.