Nobody was injured but an investigation is under way into what was considered a dangerous incident.

According to the regulator, the truck with a crane on the back simply tipped over on its side.

One of the factors being looked at is whether the load was too heavy for the vehicle.

ACT Work Safety Commissioner Greg Jones said a non-disturbance notice had been put on the site as investigations into the incident continued. Under that kind of notice, nothing can be moved until the investigators have examined evidence.

“It is very fortunate that no one was seriously injured in this incident and that the vehicle-loading crane was being operated by remote control away from the immediate vicinity of the truck,” Mr Jones said.

“The site is a residential building site that is under construction by an owner/builder and WorkSafe inspectors are currently undertaking further inquiries and investigations to determine the cause of the rollover.”

Mr Jones reminded industry to make sure safety remained a key priority as a hot, long weekend loomed.

“Safety incidents can happen quickly as seen today and it is critical that everyone on a worksite, or in a workplace, including those delivering goods or services, prioritise safety,” he said.

He pinpointed heat as a concern in general, though it's not known if it was a factor in this event.

“In terms of heat – employers should look for ways to reduce high-energy or heavy work during the heat of the day and ensure workers have adequate sun protection and breaks to cool down and rehydrate. Workers should also keep an eye on their own health and safety and that of your mates.”

He said that excess heat wasn't just an issue for outside work places but also for those working inside in places like kitchens, laundromats and where sheds or buildings are not air conditioned or properly ventilated.

“My message to all employers and workers is to make sure safety is at the forefront of all activity – be that related to supporting workers in industries impacted by the heat – or not rushing as we head towards a long weekend.

“For those in the construction sector, please ensure sites are left safe and secure for the long weekend and the site – including scaffolding and equipment, is thoroughly checked for any movement or issues before work recommences on Tuesday.”