An Indonesian rescue diver has died while searching for the remains of the 189 people killed when a Lion Air plane crashed earlier this week. Indonesia’s search and rescue agency announced the death Saturday, saying Syachrul Anto, 48, died while diving on Friday. “Deepest condolences for the passing of a humanitarian hero from the Indonesian Diving Rescue Team,” the agency’s chief, Muhammad Syaugi, said in a statement. Anto was also reportedly involved in a search and rescue mission for an AirAsia jet crash in 2014. So far, only four victims of the Lion Air crash have been identified, and divers are still searching for a second black box of the Boeing 737 MAX on the sea bed to determine what caused the disaster.