Las Vegas, Nevada (CNN) -- Principal Sherrie Gahn said she was shocked when she first came to Whitney Elementary School seven years ago.
"The kids were eating ketchup packets," Gahn said. "I said to one of my teachers, 'What on Earth are they doing?' and she said, 'That's their dinner.' "
Whitney Elementary is in a dusty, rundown neighborhood of Las Vegas known as the Boulder Strip. The main drag, the Boulder Highway, is lined with pawn shops and low-rent motels.
Families here live at the edge of financial disaster. Gahn estimates that 75 percent of her 622 students have experienced homelessness or are in danger of becoming homeless.
"There are pockets of Vegas that were bad," Gahn said, "but it's gotten 10 times worse with the recession."
Under Gahn's leadership, Whitney Elementary has become the chief lifeline for its students and their families. In addition to the regular lunch program for needy kids, the school operates a food bank.
Hundreds of students are sent home each Friday with food supplies to keep their families fed through the weekend.
"If we didn't have the food services, there would be a lot of hungry kids out there," said Kim Butterfield, a homeless advocate who works at the school.
Butterfield also organizes a clothing pantry in one of the school's spare classrooms. The school provides an entire winter wardrobe to students in need of clothing.
The school's efforts don't stop there. Gahn tries to provide whatever her students need, whether it's a dental appointment or a haircut.
"There is not an agency in Las Vegas that can actually take care of the number of homeless and poverty-stricken children that I have at this school," Gahn said. "So the only course of action I could take was to become self-sufficient."
Over the years, Gahn has built up a network of donors that supply money, goods and services. She relies on grateful parents who volunteer at the school.
Volunteer Shirley Hernandez has two grandchildren at Whitney and has seen desperate straits.
"Last year we didn't have Christmas," she said. "They gave us Christmas."
The school also paid past-due utility bills to keep the family's water from being turned off.
Hernandez is at the school most mornings, helping to fill food baskets, assisting kids who need clothes or helping out any way she can.
She said she gives back because "they helped us a lot."
Every teacher at Whitney has a story. For kindergarten teacher Michelle Olson it's the 5-year-old girl who kept falling asleep in class.
"She was getting up throughout the night to feed and diaper her baby sister," Olson said.
It may seem like a lot for an elementary school to take on, but Gahn said she has no choice.
"My goal here is to take away some of their survival needs," she said. "Then they can come to school and feel safe and learn."
Whitney is not alone. A recent survey of elementary school teachers found that two-thirds of teachers reported spending money out of their pockets to help feed hungry students.
The same survey, conducted by anti-hunger organization Share Our Strength, found that 17 million children in the United States are at risk of going hungry this year.
Whitney Elementary demands a lot in return for the special attention. Gahn said she believes her students deserve rigorous classroom instruction and the efforts are showing results.
In the seven years that Gahn has been principal at Whitney, students have doubled their proficiency scores on standardized reading tests.
"They have food in their bellies that they would not have had, they have clothes on their back they wouldn't have had and for the first time someone believes in them. It's beyond food and clothing," she said.
"It's helping them understand there are people in the community that love them and will nourish them. We want to help them create a new norm. We don't want poverty and homelessness to define who they are."