The New York City Medics are the group who have responded to 911, and every disaster since Haiti. Phil Suarez was one of the first on the ground in Haiti recently. Their web site is no brag. They have branched out into the ongoing disaster of poverty, filling 8 medical missions to Malawi this year. Their Web page is modestly informing, their reach is enourmous.
http://www.nycmedics.org/