The deadly chemical attack is the latest to hit Syria in 6 years of brutal civil war - here's what happened

One of the most devastating chemical attacks to take place during the six-year civil war in Syria has left dozens of people - including many children - dead or critically injured in the rebel-held province of Idlib.

Nearly 70 people died in what activists and Western leaders have described as an air strike conducted by the Syrian military on the northern town of Khan Sheikhoun on Tuesday, April 4.

While the United Nations and Western leaders have quickly condemned the attack, the war that's left more than 450,000 Syrians dead and 12 million permanently displaced shows no sign of ending soon. Fewer than 24 hours after the chemical attack, more air strikes started hitting the same part of town.

Here's what happened, and how the conflict escalated to this point: