Actually it wasn't a collapse more so a failure. Was listening to the whole thing come about on LiveATC.net. The pilot reported only 2 greens on approach and did multiple low flybys for confirmation. After confirmation he went well north of the airport to diagnose/repair. He reported that during subsequent gear cycles there was "snapping & clunking" from the front gear, he also tried G maneuvers to unlock the stuck gear to no avail. A final declaration of an "Emergency" followed with souls on board ( 5, 2 forward, 3 aft), and 20 minutes of fuel remaining. At first he requested 18R for landing but winds were 300 @15G18, after a recommendation from North Tower he switched over to 36L. Tower requested that he loiter over Lake Winnebago while arrivals enqueue could come in and that he burn off fuel. From the video - Pilot did a fine job bringing her in & making sure all on board safely got off.

 

At least no one was killed nor seriously injured.  Although damaged, I'm sure that A-26 can be restored to flying condition.

The tragic part is that it had just come out of a lengthy and expensive restoration...