(ALEPPO, Syria) — The Syrian army on Sunday ordered rebels in Aleppo to leave the city or face “inevitable death,” as a series of airstrikes on the neighboring Idlib province killed at least 50 people, including several children. Aleppo shook from the sound of explosions throughout the day as pro-government forces, including foreign fighters dispatched from Lebanon, Iraq, and Iran, pounded the city’s opposition neighborhoods in the east. Rebel defenses have buckled after months of siege and waves of devastating airstrikes, and the opposition could soon be driven from Syria’s largest city. It would mark their biggest defeat since 2011, when a government crackdown against dissent sparked a civil war.