WEST BLOOMFIELD TOWNSHIP, Mich. -- A high school field trip to the Cedar Point amusement park was cut short when a student became sick and admitted he ate a brownie laced with marijuana., West Bloomfield schools announced Thursday.

More than 200 West Bloomfield High School juniors and seniors went on the field trip to the Ohio park. One of them, who became so sick he had to be treated by medical personnel at the amusement park, admitted he ate a pot brownie he got from a classmate, officials said.

Chaperones have identified the student who allegedly passed out brownies but they do not know how many were brought on the buses and eaten by students.

School Principal Bob Pyles was notified and ordered the students back home five hours hours earlier than scheduled.

"When we tried to investigate an individual that we thought was the one who brought the brownies, he did not want to speak to us," Pyles said. "He would not give us much information and so with that, we had to bring the whole group back."

When the kids arrived back at the high school, their principal was waiting for them with a note.

"For the safety and well-being of all students on the trip, the trip was cut short and all students were brought back to West Bloomfield High School," the note said. "At this time, the matter is under investigation, and action will be taken against the responsible parties."

The school is investigating and the police have been consulted.