Approximately a dozen boxes, each containing $30 to $50 in change, were grabbed from classrooms. No other valuables such as computers or supplies were taken.
The theft, said Principal Kathy Kruse, has been heartbreaking.
"This is just so devastating," said Kruse. "The fact that someone would stoop so low to do this is just unbelievable. The kids are so disappointed."
The annual school fundraiser benefits the Leukemia and Lymphoma Society.
"This is something we have done for the past few years after having several students with the disease attend our school," said Kruse. "It's been something the students have been very generous with."
Since Valentine's Day, students had been bringing in their pennies and other change to their classrooms and putting them in boxes that were left there overnight. Now, as students begin the process again, the boxes are being taken out of the classrooms each evening and locked up.
"We're taking extra precautions this time, for sure," said Kruse. "We don't want this to happen again."
For fourth grader Curtis Johnson, the theft had a decidedly personal feel.
"I thought it was very sad that this happened," said Curtis, 10. "My brother is a special needs kid, so I understand."
Shevalyn Yamaguchi, 10, worried about the children who might suffer as a result of the incident. "I felt bad for all the kids with cancer who won't get this money now," she said. "It made me sad."
Students at Laurel Elementary rose to the occasion after hearing about the theft, raising approximately $300, which they brought to the Oakley campus.
"We were so touched," said Kruse. "It's a nice lesson for the students to see how something good can come out of something bad."
For information on donating to the Pennies for Patients fundraiser, call Oakley Elementary at 625-7050.