No injuries as bastion collapses over busy street
Incident probably caused by rainwater
Rescuers yesterday mounted a big operation to shift dozens of heavy stone blocks from a bastion that collapsed beneath the Argotti Gardens, in Floriana.
They feared someone might have been trapped under the debris, which spilled onto Floriana's busy Notre Dame Arch Street yesterday morning. Luckily, there was nobody.
Passersby said they heard a deafening noise before the large slabs came tumbling down over the busy thoroughfare in a dense cloud of dust shortly after 10 a.m.
The air was tense as soldiers and firemen started removing the rubble, assisted by the army's heavy machinery, as rumours that someone was buried beneath spread. A couple of hours into the operation, it was established there were no victims. However, it was well into the afternoon when all the rubble was cleared.
The bastion was extensively damaged, together with part of the garden and overhead cables, and the possibility of further collapse was not ruled out by government architects.
The masonry originally formed part of Notre Dame Gate, which was demolished early last century to make way for the street between Floriana and Pietà.
Architect Robert Musumeci, who specialises in restoration architecture, said this sort of structure was known to deteriorate when exposed to repeated cycles of heat and cold in a way that "the exposed masonry skin layers expand and contract at a different rate to the core mortar". This caused a bulge in the wall which, in turn, allowed water to seep through, washing away more binding soil mortar. Eventually, with enough rainwater, like yesterday's downpour early in the morning, a significant rise in water pressure between the bastion's skins is adequate to cause a collapse.
But the collapse was not the only problem caused by yesterday's bad weather, which, other than heavy traffic jams in the morning, saw some boats on the south coast being run aground.
Late on Wednesday morning, when gale force winds started pounding the island, a couple of boats had already broken their moorings. By yesterday morning there were more of them, a couple smashed to bits on the rocks.
kbugeja@timesofmalta.com