When Hearthom, the son of Lib, had reigned for 24 years,
behold, the kingdom was taken away from him. And he served many years in captivity, yea, even all the remainder of his days. And he begat Heth[2] in captivity, and Heth[2] lived in captivity all his days. And Heth[2] begat Aaron, and Aaron dwelt in captivity all his days; and he begat Amnigaddah, and Amnigaddah also dwelt in captivity all his days; and he begat Coriantum[2], and Coriantum[2] dwelt in captivity all his days; and he begat Com[2]. (Ether 10:30-31)
According to Warren and Palmer, beginning in the time of Hearthom, many subsequent rulers and their people actually "served" "in captivity" (Ether 10:30). This can perhaps explain why such enormous monuments were brought from the Tuxtla mountains to the site of San Lorenzo. If the time and location correlate with the account in the tenth chapter of the book of Ether, then it was perhaps the movement of these enormous monuments was work performed by slaves who happened to be direct descendants of Jared. [Bruce W. Warren and David A. Palmer, The Jaredite Saga, p. 8-20]
Ether 10:30 Hearthom . . . served . . . in captivity (Illustration): Jaredite History: From the Great Tower to Ramah. [Bruce W. Warren, "Jaredite History: From the Great Tower to Ramah," unpublished]