PITTSBURG -- Geologists in Pittsburg were scratching their heads and trying to figure out what caused a half-acre landslide Thursday morning in the southwest hills area, according to Pittsburg City Manager Marc Grisham.

Eight houses have been affected by the slide, which occurred at 7:45 a.m. along the 1000 block of Santa Lucia Drive. People living in one home were evacuated after a portion of their backyard went down with the slippage, Grisham said.

A developer in the area has offered to relocate the people living in the seven other houses affected by the slide as a precaution, Grisham said.

The city has sent an engineering assessment team and geologists to investigate the cause of the slide and the potential danger to additional homes, city officials reported. A developer has also sent geologists to the area to help with the investigation, Grisham said.

No injuries were reported as a result of the slide and property damage is still being assessed.

The city will be mobilizing all the resources needed to ensure the safety of residents in the area.

"We're trying to make sure people are safe out there," Grisham said.

Public works engineers will also be relocating a 12-inch waterline that runs through the area to provide water to a number of existing homes, Grisham said.

He said that the fact that Pittsburg hasn't had any rain in a long time makes the slide "a little more perplexing." They hope to have some answers by next week, he said.