Cornelius Frederick, 16, died at Lakeside Academy.
CNN  — 

Three staff members at a residential facility in Michigan have been charged with involuntary manslaughter after a 16-year-old was restrained, went into cardiac arrest and later died.

Two of them laid across Cornelius Frederick’s torso during restraint, causing his death, prosecutors said.

The teen was staying at Lakeside Academy, a residential treatment facility in Kalamazoo intended for young adults ages 12 to 18 placed through the foster care system or by their parents to receive behavioral health services.

Kalamazoo County Prosecutor Jeff Getting said on Wednesday evening that investigators will look at other staff members and more charges are possible.

“We needed to make sure that we assessed the case and responsibility and took action as soon as possible against those we felt were most responsible,” Getting told reporters. “We felt it was necessary to prioritize this case in a way that is seldom done.”

Frederick died on May 1, two days after being restrained by staff members, according to a $100 million lawsuit filed Monday by the family.

On April 29, Frederick allegedly threw part of a sandwich at another resident and Lakeside staff used an “improper restraint” on him, which resulted in him going into cardiac arrest, according to the lawsuit.

Geoffrey Fieger, an attorney for the family, told CNN that what happened is “horrific” and this is a case of suffocating a child.

“He committed no crime whatsoever,” Fieger said. “This cannot be acceptable in a civilized society.”

Michael Mosley, 47, and Zachary Solis, 28, and Heather McLogan, 48, are charged with involuntary manslaughter, a felony punishable by a maximum of up to 15 years in prison.

Mosley and Solis also face two counts of second-degree child abuse, each count punishable by up to 10 years in prison. McLogan faces one such charge.

Mosley and Solis restrained Frederick, Getting said. McLogan, while not physically involved in the restraint, is accused of failing to procure timely medical care for Frederick.

Getting’s office told CNN the defendants are expected to turn themselves in and are working with their attorneys to arrange that.

Don Sappanos, attorney for Solis, told CNN that his client followed procedures set down by superiors.

“We look forward to when all the evidence is released, and the video is released, that it will show my client followed the rules and procedures,” Sappanos said. “He is a gentle giant and had a great relationship with these kids.”

Kiana Garrity, Mosley’s attorney, said he also was following Lakeside’s protocol “at all times.”

“Mr. Mosley was a youth counselor – a subordinate – while others on scene were superior personnel,” Garrity said in a statement.

“Lakeside officials have released a version of events – multiple times to the media – that deflects responsibility from their own employee policies and procedures. They have attempted to control the narrative but we intend to show the entire truth surrounding the instruction and training of their youth counselors.”

There is no attorney listed for McLogan, the Kalamazoo Prosecuting Attorney’s office said, but CNN has attempted to reach out to her directly for comment.

Sequel Youth and Family Services, the owner of Lakeside Academy, told CNN that the staff’s actions were not in line with the facility’s restraint policy.

“The restraint was not conducted in accordance with our policies and training. At Sequel, it is our policy to only use restraints as an emergency safety intervention in two situations: 1) when a student exhibits imminent danger to self and 2) when a student exhibits imminent danger to others, and in those cases to use the minimal level of intervention possible.”

Video from facility shows 16-year-old restrained

In addition to eyewitness accounts, investigators reviewed two videos from Lakeside showing different angles of the April 29 incident, which began when the teen allegedly threw the sandwich. CNN hasn’t independently reviewed the videos.

Video shows that after a brief discussion between a staff member and Frederick, the teen started throwing food again, a report from Michigan Department of Health and Human Services (MDHHS) says.

The staff member then pushed him with both hands, causing him to fall to the ground. The report continues to say that several staff members then move to restrain Frederick, and some are viewed laying across his upper chest and abdomen.

At most times, the report says, “six to seven male staff” were on him. Investigators also noted that three of the staff members were “very large in stature,” the report says.

Frederick was restrained for approximately 12 minutes, according to the report. About 10 minutes in, the director of nursing came in and observed the restraints, the report continues, and about 12 minutes after the staff members released Frederick, the nurse called 911.

Frederick was transferred to Bronson Methodist Hospital where he later died, the report says.

MDHHS launched an investigation into the facility. In the full report provided to CNN, officials said that staff initiated restraint that was “significantly disproportionate” to Frederick’s behavior, and the facility did not follow its own restraint policy.

The agency has since terminated all contracts with Lakeside and has begun the legal process to revoke its license, according to a press release from the agency. At the time of the investigation, MDHHS found “10 licensing violations, including a failure to follow rules related to resident restraint and discipline,” the press release said.

In a statement, Sequel Youth & Family Services said it supports the decision to bring criminal charges. It also has said it is “making the necessary changes to ensure something like this never happens again.”

Correction: A previous version of this story incorrectly noted the number of people arrested; it is three. The story also incorrectly noted how many of those charged were involved with restraining Cornelius Frederick; it is two. This story has also been updated with the correct spelling of Cornelius Frederick's last name.