Transcript for Battling for Mosul: Inside the First Day of Fighting Against ISIS
We got a call late last night from the Kurdish president's office and being told to come up here. Around midnight we didn't know why but we assumed it was because the operation who retired muscled was about to start and sure enough just before 2 AM the Iraqi president announced. When the operation was underway. As dawn broke. Just after 6 o'clock this morning the fighting really began in earnest and and he's British press murder forces started firing artillery. Rockets mortars down. Into the valley. Down there that's the de goes of the plane's right outside of Mosul. And there are several licensed physicians down there we started seeing. An air strikes from the US led coalition jets and massive plumes of smoke. Not just from those air strikes and explosions but also from. The oil and tire fires. Debt crisis is setting to provide themselves some sort of cover the middle of the day got very heavy did that the fighting was very intense we started hearing lots of machine gunfire indicating. Besides working Casey. And then it got very quiet in the afternoon we understand ice has lost several villages around Mosul today but they're not gonna go down without a fight this is crisis as the last major stronghold. In Iraq if they lose Mosul. There really don't have anything but the question now is whether they're actually gonna put up a real fight me. Foremost ordered it recognized the force that is coming in against them. And in my case would then turn around. Head out to Syria and live to fight another day.
This transcript has been automatically generated and may not be 100% accurate.