The death toll in a tsunami that battered Indonesia’s Sunda Strait over the weekend has nearly doubled, with at least 429 people confirmed dead Tuesday as authorities warned residents that volcanic activity could trigger further destruction. Another 154 people remain unaccounted for, with officials reportedly privately admitting that it’s unlikely they will be found. As thousands of rescue workers combed through the wreckage, heavy rains reportedly slowed down efforts to find victims who may be trapped underneath the debris. The catastrophic tsunami—which hit without warning and is believed to have been caused by an eruption of the Krakatoa Volcano—wiped out hundreds of homes and prompted some residents to demand authorities do more to prevent such disasters in the future. Kunto Wijoyo, the director of the Tanjung Lesung beach resort, where the pop band Seventeen was playing when the tsunami pummeled the area, told The Guardian authorities should build a dam to protect the area. He said he helped rescuers retrieve more than 100 bodies in the aftermath of the disaster. “There were men, women and babies,” he was quoted as saying.