Work place incident

Today in work a large piece of extraction piping fell, approximately 40-50ft in length 1-2ft diameter it fell from an approximate height of 25 ft onto an area where someone might normally be working and also a walkway. It's pure luck that noone was hurt, there were people within 3-6 feet of where it fell.

From what i can see the sections were filled with dust and debris, a byproduct of the work carried out here, i'd say half to three quarters full, without doubt enough to kill or seriously injure someone. It looks like the weight was to much for the supports in place.

From what i can make out this is classed as a dangerous occurrence on the HSA website.

I queried in work with my supervisor and manager whether it should be reported and was informed that because noone was hurt they werent sure and the Health and safety officer was checking it out. I was told that the insurance company had been informed.

The mess and pipes and immediate area were/ are cordoned off. The mess was cleared up and pipes moved within an hour.

Work was allowed to continue in the areas immediately adjacent to the incident despite identical piping being above every working area and no guarantee given regarding the safety of the other piping.

My questions are,
1) is this a reportable incident?
2) should the H and S officer know this immediately?
3) should we have been left back to work before our safety is assured?
4) should the incident have been tidied up before the HSA were informed?