It appears that Hiel built the whole city, which is an indication of the progression of his sin. Matthew Henry wrote, “He went on to build, in defiance of the execution of the curse in part; for, though his eldest son died when he began, yet he would proceed in contempt of God and his wrath revealed from heaven against his ungodliness."1
34 In his days Hiel of Bethel built Jericho. He laid its foundation at the cost of Abiram his firstborn, and set up its gates at the cost of his youngest son Segub, according to the word of the LORD, which he spoke by Joshua the son of Nun.