The hunger crisis in Gaza under Israel’s assault has reached a “tipping point,” experts and advocates tell NBC News, with deaths expected to soar if Palestinians do not get urgent relief.

And many children who do survive malnutrition will face lifelong consequences, they warn.

The “window to prevent mass death is rapidly closing, and for many it’s already too late,” said Kiryn Lanning, senior director of emergencies of the International Rescue Committee (IRC), a U.S.-based humanitarian organization. The World Health Organization warned that the “health and well-being of an entire future generation” was at stake.

Doctors and aid workers inside Gaza, themselves overworked and underfed, have been warning for months about the critical lack of food and the spiraling cost of the little that was available due to Israel’s offensive and crippling aid restrictions. They say that their worst fears are coming to pass.

“We are now facing a massive health disaster,” Dr. Ahed Jabr Khalaf, a pediatrician and intensive care specialist at Nasser Hospital in Khan Younis, told NBC News’ crew on the ground. He said Wednesday that several more children had died from malnutrition that day alone.