KHERSON, Ukraine (AP) — Floodwaters from a collapsed dam are still rising in southern Ukraine. Hundreds of people have been forced to flee their homes in a major emergency operation that has brought a dramatic new dimension to the war with Russia, now in its 16th month. Officials said the flood’s force was expected to slacken Wednesday following Tuesday’s breach of the Kakhovka hydroelectric dam and reservoir, which is one of the largest in the world. Even so, authorities said water levels were expected to rise by another meter (about 3 feet) over the following 20 hours. Some local residents spent the night on rooftops. Others, scrambling to flee the rising waters, were evacuated by buses and trains with the belongings they could carry.