LOS ANGELES (AP) — Two former high school students who lost fingers in a tug-of-war accident have sued a Southern California school district.

Seniors Pablo Ocegueda and Edith Rodriguez were taking part in a Spirit Week contest in February of last year at South El Monte High School when the rope tore off some of their fingers.

Reports at the time said they lost at least four fingers each.

City News Service says their lawsuit, filed Thursday in Los Angeles, contends that school officials failed to properly supervise the contest and allowed the students to grab a slipknot on the tug-of-war rope. The suit says the knot slipped, causing the injuries.

School Superintendent Nick Salerno issued a statement saying he couldn’t immediately comment.