"I was once homeless," is how Christopher Axe always introduced himself to students in his English class.

Lindsay Sobel, a 17-year-old girl living in Chatsworth, California, has collected nearly 30,000 pairs of worn down shoes and came up with the idea of "Shoes for Souls", a charity that helps homeless people in her hometown.

Christopher Axe, a British expat in Hanoi established a voluntary group to help the homeless in the city. The group has so far drawn the participation of more than 6000 members.