`` I was there -LSB- El Salvador -RSB- as family members identified the bodies of family members pulled from the rubble . It 's something that you can never forget . I ca n't imagine hundreds of thousands of people going through that now . '' For people like Scheidler , the news from Haiti is n't abstract . It 's personal . They are people who have either survived natural disasters or respond to them . The Haitian earthquake has forced some of them to think again about the survival lessons they learned , and what Haitians face in the days ahead . How disaster brings out best , worst in human nature Several say disasters can reveal the worst in human nature . Patrick Johns traveled to Indonesia in the immediate aftermath of the 2004 Tsunami . He 's also traveled to Ethiopia to aid in famine relief and Rwanda after the country was decimated by genocide . Johns , who is now the director of emergency response for Catholic Relief Services , said it is critical to immediately establish security right in Haiti . `` Crime is a problem in Haiti even in the best of times
-LRB- CNN -RRB- -- At first , Kip Scheidler said he felt the ground tremble . Then the roof began to shake . Tiles tumbled from the ceiling as people bolted from their chairs to escape . When Scheidler tried to follow them , he could barely keep his balance as the ground wobbled . `` The weird thing is that afterward you will swear that it lasted 20 minutes but it really lasted 60 seconds , '' Scheidler said of the earthquake tremors . `` But at the moment , it seems like it will never stop , and it keeps getting stronger . '' That 's how Scheidler remembers one of the most horrific moments in his life -- the 1986 earthquake in El Salvador that killed 1,500 people . All those memories came flooding back recently when Scheidler turned on CNN and saw images from this week 's earthquake in Haiti , which may have killed at least 100,000 people , according to initial estimates . `` I was sickened by the news , '' said Scheidler , now the senior director for global disaster response for Habitat for Humanity International , an international relief agency .