The U.N. warns the humanitarian crisis in Gaza is growing more acute. In southern Gaza, a quarter of the population faces catastrophic levels of food insecurity and in northern Gaza, nearly one in three children are severely malnourished. Nick Schifrin discussed more with Martin Griffiths, the U.N.'s top humanitarian official, about what he calls one of the worst years for humanitarian crises. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders