At least 81 people are dead and 870 are still unaccounted for in the massive wildfire that has brought devastation to Northern California, the so-called "Camp Fire."

Fire officials say Wednesday's rainy forecast might help them fight the flames.

However, the week-long heavy precipitation could also cause mudslides, making recovery efforts more difficult.

"We've had to employ over 400 different search teams from various counties, even interstate partners as well," said Rick Crawford with the California Department of Forestry and Fire Protection.

"The area is broken down into a gridded section," he explained. "And each grid will be given a search team and then they will go from property to property looking for any evidence of human remains."

"The task is arduous. And the possibility exists that some people may never be found," he warned.

The National Weather Service has already issued a flash flood watch for several towns, including Paradise. The retirement community, which was home to 27,000 residents, was utterly destroyed by the Camp Fire.

"Given the weather and the time frame, we're up against the clock," USA Today quoted Jason Solak, rescue-team manager for California Task Force 4.

The fire, which has burned at least 236 square miles and destroyed nearly 13,000 homes, is now 75 percent contained.