PORTLAND, Ore. – Students were released early from Cleveland High School on Tuesday due to a raw sewage backup.

A letter from Principal Tammy O’Neill was posted on Facebook at around 1:30 p.m.

"A suspected main sewer line blockage has resulted in a raw sewage back-up and a water system shutdown," O'Neill wrote in the letter.

She said the school was working to get buses to take students home as soon as possible. Students who couldn’t get in contact with family or take a bus home were being kept at the school until they could go home safely.

After-school activities, including athletic events, scheduled at Cleveland High School Tuesday afternoon were canceled. Events away from the school continued as scheduled.

On Tuesday night, Portland Public Schools tweeted the sewer lines were unclogged and classes would resume as normal.

Read the full Facebook post: