NORMAN, Oklahoma - The Norman school principal who was behind the wheel of a bus when it crashed, is now retiring. 

Parents at Cleveland Elementary received letters Wednesday announcing their principal's early departure.

“I just kept hearing alert, after alert, after alert, I thought the world is blowing up,” said mother Leslie Draper.

Following the announcement, Draper was bombarded with emails.

“My first thought is oh, thank God, children can be safe now. Then, my second thought is what does this mean?” said Draper.

In the letter, Cleveland Elementary Principal Ty Bell attributes his early departure to a combination of things including, "a difficult year compounded by the painful loss of several close family members..."

He goes on to say, "it is time for me step away to focus on my family and the restoration of my own, personal health."

“I want to know how is he being held accountable, how was letting him retire holding him accountable? How is it protecting the next group of kids?” said Draper.

Draper's daughter Piper was 11, when her school bus crashed in September 2018 while on a field trip in Texas. Principal Bell was behind the wheel.

Since the accident, Piper along with several of her classmates continue to heal.

“She has night terrors at least four nights a week, she has panic attacks at least two to three a day, we have not left that bus crash,” said Draper.

Draper said while Bell attributes a stressful year and personal matters to his decision to retire early, she and others believe there's more that has yet to come to light.

“Someone pulled on a string and because someone pulled on that string the entire facade is now crumbling, there will be a lot made known in the next few weeks and months that have been hidden,” said Draper.

The crash was deemed an accident. Payment for those injured in the crash is capped by the district's insurance at one million dollars to be split among the families.