DENVER >> A coach shown pushing cheerleaders down into splits on video in Denver was fired from another Colorado high school last year because of concerns about his techniques.

Ozell Williams is one of five school workers who have been placed on leave after the videos from East High School were made public and police opened a child abuse investigation.

Williams, the founder of a Denver-area tumbling school, worked as a contract employee with cheerleaders at Boulder High School during two stints in 2015 and 2016 to help them with choreography and tumbling. He worked with the cheerleaders once or twice a week in the fall of 2015 and also during a summer camp in 2016. He was dismissed three days into the four-day camp after a coach saw him using a technique similar to that seen in the Denver videos, said Randy Barber, a spokesman for the Boulder Valley School District.

A mother had also emailed the head coach, who was out of town at the time, about the technique, sometimes referred to as “breaking”, but he wasn’t fired until after another coach observed him using the technique with students.

Barber said administrators did not learn about the problems until this week when the videos were obtained and broadcast by Denver’s KUSA-TV.

Boulder High’s principal, James Hill, sent a letter to parents on Thursday asking anyone who had a problem working with Williams to tell administrators or police.

The videos show eight cheerleaders repeatedly being pushed into splits while their arms are held up by teammates. In one video, a girl repeatedly asks her coach to “please stop.” The TV station says the videos were shot on the phones of two team members and were sent anonymously to the station.

In Boulder, the head coach downplayed the mother’s concern about whether it was normal for Williams to break students so soon. In an email released by the district, the coach told her that Williams “has done it to the other girls along with many others and has had no issues” but that students don’t have to do anything they’re not comfortable with.

However, according to Jim Lord, director of the Cheerleading Coaches and Administration Association, the practice is outdated, damaging and rare. He also said he had never heard of the term “breaking.”

“While it is possible that some coaches have a perception that this is common within their small circle, it should be clear from the overwhelming number of coaches across the country who have come out against this that it is not a common occurrence. If anyone still harbors that opinion, this incident should help make it clear that it is not acceptable,” he said in a statement Friday.

Williams couldn’t be located for comment but he told The Denver Post on Thursday that the videos were taken out of context.

“You can definitely say that what was in the video could be seen in a different light,” he told the newspaper. “I would love to tell my story, but I can’t say anything else at this time.”

Williams graduated in the spring from the University of Colorado and often performed tumbling tricks before football games there. In a TEDx talk at the school last spring, he spoke about how a mentor he met while growing up in Chicago helped him develop his tumbling talent and how his skills provided an escape from a difficult childhood.

In addition to Williams, the East High School principal, an assistant principal, the cheer coach, an assistant cheer coach and a district lawyer are on leave during the investigation into the videos.