(CNN)When 9-year-old William McLeod went to his Utah public school on Wednesday, he knew some of his classmates might ask him about the ashen cross he wore on his forehead for Ash Wednesday.

He didn't think his teacher would tell him it was inappropriate and make him wash it off.

"It was really bad," William told CNN by phone Friday. "I went to the office and I was crying and I felt like I was in trouble."

William's teacher has been placed on administrative leave while the Davis School District investigates, officials said in a statement, calling the teacher's actions "unacceptable."

The teacher told him his ashes were 'inappropriate,' grandmother says

William's grandmother, Karen Fisher, said he went to school after an Ash Wednesday Mass at their Catholic church.

During the service, William, like legions of faithful all over the world, had an ash cross placed on his forehead to mark the beginning of Lent, a season of prayer and penance that Christians observe ahead of Easter.

Fisher told her grandson he didn't have to get the ashes if he didn't want to. And if he went to school with them, she told him, people would probably ask him about what the symbol meant.

"People are going to look at you like you've got dirt on your head," she explained to him, "and that's OK. You explain this is Ash Wednesday and you're a Catholic. And he goes, 'OK, I want to wear them.'"

William McLeod stands in front of a crucifix in this picture taken by his grandmother, Karen Fisher.

It was his first time getting ashes on his forehead for Ash Wednesday, William told CNN.

But hours later, Fisher got a call from the school's principal, who told her that William's teacher had asked him what was on his forehead, and he told her it was an ash cross for Ash Wednesday. She told him it was "inappropriate," Fisher said, "so take it off."

The teacher handed William an antiseptic wipe and made him remove the ashes in front of his peers, Fisher said.

"I was furious," she told CNN. "This is who we are. This is part of our life as Catholics."

Fisher noted there's a large Mormon population in Utah, but she said she's lived there for decades, and nothing like this has ever happened to her.

"I was just kind of shocked," she said.

The school district and teacher apologize

William went to the school counselor, who made it clear he was not in trouble and had done nothing wrong, the boy told CNN.

The Davis School District has apologized for the ordeal.

"We are sorry about what happened and apologize to the student and the family for the teacher's actions. The actions were unacceptable," according to a statement Friday to CNN. "No student should ever be asked or required to remove an ash cross from his or her forehead."

The district added that it called its director of educational equity, who is also an ordained Catholic deacon. He reapplied the ash cross to Williams' forehead that afternoon.

Asked whether that made her feel better about what had happened, Fisher said, "Yes and no."

"We all have our different beliefs," she said, "and we all have to be respected for that."

William's teacher also apologized, with a note asking if they could move forward, he said. That was something he appreciated.

"I accepted her apology. I kind of feel bad for her," he said. "She's a great teacher, and I don't want her to lose her job."

Asked whether he'd get ashes placed on his forehead next year, William didn't hesitate: "Yes," he said.