Way off topic, but scaffolding is not low risk. Its safe as long as you don't fall, which which takes a lot of skill and confidence (at the heights i routinely work at even dropping a spanner could kill someone), and wearing and correctly using a harness is no guarantee of surviving a fall as the blood in your legs turns toxic due to the harness cutting off circulation. The time this takes to happen varies from person to person but the lower limit is around 15 minutes (some people can last a lot longer).
Remember kids, being in the construction industry is more dangerous than being a cop (at least in New Zealand)
Machines that have broken down will work perfectly when the repairman arrives.