The upper part of Saqqajja Hill, in Rabat, has been closed to traffic after a retaining wall collapsed during Wednesday's storm.
Several parts of Malta experienced unseasonal downpour on Wednesday morning and afternoon as well as a drop in temperature.
Infrastructure Malta said on Thursday that its architects and technicians were investigating the collapse of the retaining wall.
Part of Saqqajja Hill road, were it merges with Nikola Saura Street, will be closed until further notice. Emergency repairs will kick off soon.
IM urged motorists to follow diversion signs to nearby alternative routes. Those headed to Dingli should take the Mtarfa Bypass (Triq il-Maltin Internati u Eziljati) and then Il-Haddiem Avenue.
Access to Mdina and Il-Kbira Street, towards the centre of Rabat, will remain open.