The family of freed American hostage Keith Siegel said he was deprived of both food and sunlight during his 15-months hell. Now, the 65-year-old North Carolina native is eager to help the hostages still under Hamas captivity in any way he can.

It is believed that at least two of the six American hostages still held in Gaza are alive — Sagui Dekel-Chen, 35, who grew up in Bloomfield, Connecticut, and Edan Alexander, 19, from Tenafly, New Jersey. Four other Americans are believed to have been killed in captivity.

Keith Siegel, a dual U.S.-Israeli national, was released Saturday along with two other hostages in the third exchange between Israel and Hamas under the ceasefire.