 The native Hawaiian people of the area were called Ke Awalau o Puʻuloa . They used the island to cultivate watermelon and to harvest pili grass for the construction of thatched roofs . According to Hawaiian legend , the goddess Kaʻahupahau killed a girl on the island ; remorseful , she then proclaimed a law forbidding further killing . Kaʻahupa @-@ hau 's brother Kahiʻuka ( sometimes referred to by historians as her son , Ku @-@ maninini ) was said to live in an underwater cavern off Ford Island with Kanekuaʻana , a giant water lizard which supplied food to the people of ʻEwa Beach . 
