TIJUANA – Unstable ground gave way in two southern neighborhoods Tuesday afternoon, leading to the collapse of seven houses, authorities announced even as they prepared for a new storm set to arrive overnight.

The inhabitants were able to evacuate their homes in the Cumbres del Rubí and Anexa Ramírez colonias, and there were no casualties, said Antonio Alfaro, deputy director of the city’s emergency agency, Protección Civil.

The homes were built without authorization in the canyon area. For years, authorities have warned the residents that the structures were at risk of collapsing.

During last week’s storms, they advised them to leave.

Alfaro said that landslides occurred in the area in 1996 and 2003. And five years ago, the families were told to evacuate and the houses were tagged warning of imminent collapse, Alfaro said.

The residents who fled the houses Tuesday are staying with family members or friends while city authorities help organize a more permanent solution.

The emergency agency warned people living near unstable areas to leave because they could collapse as the ground becomes more saturated in the new storm.