Indiana mom: Son was left strapped in school bus for 2 hours

“I didn't know if I'd ever see him again,” Collin said. “I didn't know if he walked off and I was thinking how far he could have gone in two hours. I didn't know if he ran out in the parking lot or if someone grabbed him. It's cold out. How long could a child last in the cold?”

Collin had sent her son to West Lake Special Education Cooperative on Tuesday morning, the Times reported. She went to the school around 10:30 a.m. to surprise Luke at the scholastic book fair, but was shocked to hear school staff members say they thought the boy was at home.

"I was screaming, I felt like I couldn't breathe," Collin told the Times. "They kept telling me to calm down because I'm pregnant. I know I'm pregnant. I know the baby in my belly is safe, but where's my 3-year-old son?"

The school was put on lockdown as school officials searched for Luke. He was found at the bus barn.

School Town of Munster Superintendent Jeff Hendrix said the boy was found "unharmed and warm by bus facility personnel" School Town of Munster Superintendent Jeff Hendrix said. He was on the bus for 80 minutes, officials said.

"Terrible," Scott Collin, Luke's dad, told the Times. "They called me and told me my wife was frantic. That she was freaking out because we lost your 3-year-old and she needs to calm down because she's pregnant. I said, 'What do you mean you lost our 3-year-old?' There was no compassion."

Hendrix said the school is investigating the incident.

"We are currently investigating the incident to determine if all procedures were followed. Upon completion of the investigation, if it is determined that our policies and procedures need to be updated or rewritten, then we will do so," Hendrix told the newspaper. "Our goal is to ensure that all students are kept safe at all times during their transportation to and from the School Town of Munster, as well as, the time spent in our buildings during the school day."