ONTARIO, Calif. (AP) — Searchers probed a flooded basin Friday in a lengthening search for four people believed to have been swept down a wash during the powerful storm that drenched California early this week.

The search began Tuesday when 10 people, believed to be homeless, were swept down a flood control wash in Ontario, about 35 miles (56 kilometers) east of Los Angeles. Five were rescued and one was found dead, authorities said.

Searchers from the Ontario Fire Department focused on a settling basin that was turned into a lake by the storm runoff.

Members of the urban search and rescue team walked the banks and a police helicopter and drones were being used to look down into the water, said Dan Bell, the city’s director of communications.

In addition, water was being drained from the basin, he said.

There has been no determination of how long the search will continue, Bell said.

“We’re still moving forward on searching daily,” he said.

Southern California weather was forecast to remain dry into next week.

Parts of Northern California were expected to get some precipitation Friday night and Saturday from a quick-moving system, but forecasters said impacts would be far less than the previous storm, which delivered enough snow for many ski resorts to move up their opening days.