Risk Management Solutions Inc. warned Monday that the "most likely location" of the next big earthquake to affect the San Francisco Bay area is on a fault running east of the bay, which could cause $25 billion in insured losses if there is a tremor the size of one that hit the area 146 years ago.Newark, Calif.-based RMS also warned that a magnitude 7.9 quake on the San Andreas could cause more than $200 billion in losses. All figures are in United States dollars.