The three—Seán Savage , Daniel McCann , and Mairéad Farrell ( members of Provisional IRA Belfast Brigade ) —were believed Know to be mounting a car bomb attack on British military personnel in Gibraltar .

According to the United States Geological Survey Scrutiny ( USGS ) the cities experiencing Perception_active the strongest shaking—VIII ( `` Severe '' ) on the Mercalli intensity scale ( MM ) —were Concepción , Arauco and Coronel .