What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Aircraft VFR arrival to kpao, flying the profile of GPS 31 approach (straight it to 31). Pilot said normal pre-landing checks completed, gear down, green light, 3 wheels visually confirmed and hydraulic pressure up. Normal landing was executed in the touchdown zone. On rollout, after cresting a hump in the runway (kpao runway is built on bayland fill and is not flat, there are multiple large undulations), the left main gear collapsed and the left wing float contacted the runway. Aircraft veered left and came to rest between the centerline and the left edge of runway, between twy b and c. pilot shut down the engine and master switch. Pilot said the gear handle appeared down, but hydraulic pressure was indicating zero. When the pilot turned the switches back on and pressed the gear handle down, it moved slightly further down and saw hydraulic pressure coming back up.
As the FAA filed it
AIRCRAFT VFR ARRIVAL TO KPAO, FLYING THE PROFILE OF GPS 31 APPROACH (STRAIGHT IT TO 31). PILOT SAID NORMAL PRE-LANDING CHECKS COMPLETED, GEAR DOWN, GREEN LIGHT, 3 WHEELS VISUALLY CONFIRMED AND HYDRAULIC PRESSURE UP. NORMAL LANDING WAS EXECUTED IN THE TOUCHDOWN ZONE. ON ROLLOUT, AFTER CRESTING A HUMP IN THE RUNWAY (KPAO RUNWAY IS BUILT ON BAYLAND FILL AND IS NOT FLAT, THERE ARE MULTIPLE LARGE UNDULATIONS), THE LEFT MAIN GEAR COLLAPSED AND THE LEFT WING FLOAT CONTACTED THE RUNWAY. AIRCRAFT VEERED LEFT AND CAME TO REST BETWEEN THE CENTERLINE AND THE LEFT EDGE OF RUNWAY, BETWEEN TWY B AND C. PILOT SHUT DOWN THE ENGINE AND MASTER SWITCH. PILOT SAID THE GEAR HANDLE APPEARED DOWN, BUT HYDRAULIC PRESSURE WAS INDICATING ZERO. WHEN THE PILOT TURNED THE SWITCHES BACK ON AND PRESSED THE GEAR HANDLE DOWN, IT MOVED SLIGHTLY FURTHER DOWN AND SAW HYDRAULIC PRESSURE COMING BACK UP.