Scaffolding is a pretty commonplace thing.

Sometimes in north London — with the endless extensions, redevelopments, excavations — it seems that there are boarding and railings on every corner.

Most scaffolding doesn't collapse.

But it is precisely because it is so commonplace that the people of South End Green need to be told what went wrong with the scaffolding that fell on March 7.

There's new scaffolding there again today, and without knowing why its predecessor failed in high winds this spring, or the steps taken to make sure this one does not come crashing down too, how can passers-by be confident in their own safety?

As this newspaper heard both in March and this week, we were very lucky indeed that - miraculously - no-one was hurt.

But clearly something went badly wrong, and while we can speculate as to the failings that left the scaffolding vulnerable to high winds, we still don't know, either exactly or officially, why.

When we first approached the Health and Safety Executive about this incident, it emphasised "they would not be providing a running commentary" on their probe.

This is all well and good - but it is hard to see why it has not been able to conclude its investigation yet. In the hours after the scaffolding collapsed, the contractor who erected it had a theory, and this was repeated by many casual observers. But if this was the case, why were the conditions in place for this to happen? We still have no idea.

If the HSE needs more time, it should be telling us that, and why- which in itself would be instructive.

Every extra day it takes the HSE to come to a conclusion is a day in which the people of NW3 will be questioning their safety.

And, more importantly, every day longer is a day without the HSE recommending reforms, rule changes or tighter scrutiny that could stop this happening again.

Next time there might not be a miracle.