JERUSALEM — At least nine Israeli teenagers on a “bonding” trip were killed, and one was still missing, after a flash flood swept them away on Thursday while they were hiking in a riverbed near the Dead Sea.

Rescue workers, soldiers and volunteers in helicopters, jeeps and rubber boats and on foot frantically searched for the missing teenager as night fell in Wadi Tzafit, a popular hiking destination in dry weather that can become a death trap with little warning in a rainstorm.

Two youths were hospitalized for hypothermia and other injuries, and 13 were rescued unharmed, officials said. The fatalities were reported by Zaka, an Israeli rescue and recovery organization. Eight of the teenagers who died were women and one was a man, according to Israeli media reports.

A lack of regulatory oversight of the academy that arranged the field trip led quickly to recriminations between the Defense and Education Ministries, which share responsibility for approving such programs. The Israeli news media published text messages in which some of the teenagers expressed fears about the outing, and organizers reassured the doubters that they were well prepared and had the authorities’ approval to go ahead with it.