12 people have died since snowstorms hit San Bernardino Mountains, authorities say

SAN BERNARDINO, Calif. (KABC) -- Weeks after powerful snowstorms pummeled the San Bernardino Mountains, 12 people have been found dead, authorities said Wednesday, with only one being a weather-related death.

Earlier on Wednesday, the San Bernardino County Sheriff's Department told ABC News that three people were found dead in separate welfare checks.

An updated statement from the Sheriff's Department increased the number of deaths to 12.

"To date, we have identified 12 individuals who were deceased. So far, we can only confirm (1), a traffic accident, as weather related," the Sheriff's Department said. "The preliminary information in the other deaths does not indicate they are weather related, but those investigations are ongoing."

Authorities say they continue to respond to calls for service and will provide further updates if they have more information.

Rare blizzard warnings went into effect in late February in the mountain ranges of Southern California as an arctic air mass plunged down the West Coast, plastering California's coast ranges and the Sierra Nevada.

In an extremely unusual event, staggering amounts of snow fell in the San Bernardino Mountains and the adjacent San Gabriel Mountains, where thousands of people live or visit communities at high elevations reached by windy, steep highways.

In the aftermath of the storms, residents found themselves unable to leave their homes.

San Bernardino County authorities said the snowfall was so great it exceeded the capability of plows to clear roads, requiring earth-moving equipment and dump trucks to pick up and move snow.

The Associated Press contributed to this report.