DescriptionVietnamese immigrant and billionaire businessman says migrants will rebuild Houston as he donates $5million to help the most vulnerable survivors of hurricane Harvey.A Vietnamese billionaire who came to the US as a refugee has donated $5million to the victims of hurricane Harvey. Kieu Hoang, 73, who lives in California, said the gift was his way to 'pay back' to America after he was able to flee the Vietnam war by settling here in 1975.His money will be used to transition some of Harvey's most vulnerable victims - the elderly, poor and those with special needs - from temporary shelters into permanent housing, Houston mayor Sylvester Turner said.At a press conference on Monday, Hoang said: 'I am here to thank the American people who allowed me to come to this country as a refugee in early 1975 at the age of 31.'I am here to pay back, contribute and show my gratitude to this great country.'Speaking to the Houston Chronicle, he added: 'Dr. Martin Luther King said 'I have a dream. "Thanks to the American people's help, I have realized some small dreams. 'A dream to have immigration laws so that a lot of people do not live in constant fear of being deported. A dream to allow immigrants like me to come into this great America to make it greater, and the greatest.'Did you realize a lot of Houstonians dared not to check into shelter centers for help, as they are scared to be discovered and deported? God help America (to) help them. For Houston, who will help rebuild the city?'Hoang's first job after coming to the US paid just $1.25 per hour, but he now owns the Rare Antibody Antigen Supply company, which is worth $14billion.He has a personal worth of around $3billion, according to Forbes.Harvey killed an estimated 50 people, destroyed approximately 200,000 homes over a 13-mile stretch of land and displaced more than 1million.The governor of Texas has warned that the total bill to clean up the devastation could be as high as $180billion.