Motorists were shocked but unhurt on Tuesday afternoon when a big block of concrete slid off a flat-top truck near Żejtun.
The incident happened at about 2pm as the truck was going round the roundabout near Montebello car showroom.
People on the scene said the block did not appear to have been secured.
Such incidents are becoming relatively frequent. In July, a block of similar size fell off a truck at the roundabout known as Tal-Erba’ Mwieżeb in St Paul's Bay.
A similar incident happened at Corradino Hill in April.