Before the Battle for Mosul began in October of 2016, there were nearly one and a half million civilians in living in Iraq’s second most populous city and the Islamic State’s last major stronghold after Raqqa. The city and its civilian population are divided into an eastern and a western segment by the River Tigris; the eastern side and its roughly 400,000 citizens have been free since a one hundred day offensive led by the Iraqi army ended in January. The Western section, which is still populated by between 650,000 and 800,000 civilians, is the object of a joint push by Iraqi, Turkish, and Kurdish troops and US air support.

The long-suffering civilians of the city have no safe route of escape; however, somewhere between 28,000 and 31,000 civilians have fled the city since the conflict began. This is largely motivated by the fact that, in addition to the extreme risk of violence posed by the fighting and the more than two hundred car bombs detonated in Mosul since the conflict’s outbreak, food and water are running out. Humanitarian officials are especially concerned as more than one half of the nearly 200,000 civilians who have fled since October 2016 are children.

Coalition forces outnumber Islamic State combatants by approximately twenty-to-one. Experts contend that the Islamic State becomes more violent and unpredictable as its opposition becomes stronger. Twelve people were treated by the International Red Cross after they were attacked with what seems to be a chemical weapon similar to mustard gas on Friday. The World Health Organization is also investigating and preparing to respond to future attacks. The Islamic State has carried out similar attacks against United States and Kurdish forces in the past.

The battle for the western part of the city, which was estimated to take at least as long as the battle for Mosul’s significantly less populous eastern section, may take longer than expected and drive the number of civilian casualties up. Civilian casualty estimates for the Battle for Mosul are not yet accurate, but nearly 7,000 Iraqi civilians died from terrorism or war last year. Many experts, included the United Nation’s humanitarian coordinator for Iraq, estimate that the ratio of civilian to combatant casualties will be significantly lower, with more civilians dying than usual, due to purposeful targeting of civilians by the Islamic State in Mosul.

There is some cause for hope. This push, if successful, will continue the forward momentum that has diminished Islamic State control of Iraq from approximately forty percent to ten percent.