Israeli planes dropped leaflets over northern Gaza this week, telling civilians to leave their homes and move south.
Footage taken for Scripps News Friday shows the exodus already underway.
Streets are clogged with cars piled with mattresses and pedestrians fleeing on foot. There are families, and small children.
Gaza residents interviewed by the Associated Press say it's a near impossible task.
"They threw down leaflets saying everyone has to leave. They will annihilate the area with anyone in it," one man said. "What did the women do to be terrorized like this? What did they do wrong?"
Israel at War: A Scripps News special report
Scripps News reports from Israel, where an escalating war with Hamas has killed thousands and triggered a humanitarian crisis.
The warning comes as Israeli tanks and troops mass on the border ahead of a widely anticipated invasion.
Gaza has a population of more than 2 million people, half of them under the age of 18. An estimated 1.1 million live in the area Israel wants cleared of civilians.
At 25 miles long and 7 1/2 miles wide, Gaza is about twice the size of Washington, D.C.
There's no way out. All the border crossings with Israel are closed, as is the crossing into Egypt — the Raffa Gate on the southern edge.
Footage shot for Scripps News shows a city that is being systematically destroyed by Israeli air strikes. A hospital inside Israel's evacuation zone is being overrun with the dead and the wounded.
But despite the extreme danger of traversing an active war zone, civilians are attempting to move south, in cars, taxis and on foot.
UN relief agency pleads for 'life-saving' humanitarian aid to Gaza
The United Nations Relief and Works Agency called the urgent plea for donations a flash appeal for necessary funding for its core budget.
One man, fleeing northern Gaza with his children after Israel's warning to move south, told a reporter he is leaving "because of what is going to happen. May God bring relief to everyone."
Aid groups are warning that the mass movement will be a humanitarian disaster — but the people of northern Gaza have few other choices.
Appearing on Morning Rush from Gaza city, Colorado pediatrician Dr. Barbara Zind says her work with the Palestine Children's Relief Fund has been difficult in recent days.
""It's an endless barrage of missiles and bombs, all falling on civilians," Zind told Scripps News. "People live so much on top of each other — it's just so scary thinking of families being in a situation not having a place to go, and just being so afraid of destruction and harm."
Zind says kids are particularly vulnerable.
"I tell you that those 2.3 million people, half of them are children. So that's a lot of children. First of all there's physical things. They are barely getting medications sparingly, struggling on a good day before this bombardment. Kids with chronic diseases — they've been having trouble getting insulin on a regular basis. And now with this, a lack of supplies, we know it's going to be even more devastating. You're right. They're trying to find a place to refuge. They go to the UN schools but even those are under bombardment. It's indescribably scary for a child."
