Arlington police are investigating after a north Dallas day care center forgot a five-year-old boy inside AT&T Stadium Thursday.

Leonardo Moncada, 5, went with a group of around 40 children from Jeanette’s Little Haven Christian Academy to the stadium Thursday for “Kids Day” – where around 2,000 kids from approximately 100 North Texas day cares and schools came for tours and a day of fun.

Somehow Moncada became separated from his group, and stadium security later found him wandering alone on the football field.

“What’s unusual is the fact that we haven’t received a phone call yet,” said Sgt. Christopher Cook of the Arlington Police Department about the department’s frustration that the day care had yet to come forward as of 7 p.m. Thursday. “We’re almost two-and-a-half hours into the call.”

"This was a shocking mistake and heads are gonna roll"- daycare owner to hold emergency meeting after boy left alone at @ATTStadium @NBCDFW — Jeff Smith (@JeffSmithi24) August 14, 2015

Shortly after 5 p.m., NBCDFW was there to watch three Arlington police officers escort Moncada out of AT&T Stadium – even taking time to toss a football with him and allowing the boy to activate the lights and siren on a squad car.

“So that he could kind of see what police officers do, and to keep his mind off the fact that he had been left at the stadium,” Cook said.

Police officers took Moncada to the department’s headquarters where he waited for approximately three hours until his mother, Erica Corbin, arrived.

Corbin told NBCDFW she had no idea any of this was going on until she showed up to Jeanette’s Little Haven.

“I went to pick him up and when I went into room where he normally is [and] I didn’t see him,” Corbin said. “I don’t understand how they wouldn’t realize he’s not there.”

Corbin wasted no time wrapping her young son in a hug when he emerged from behind the Arlington Police Department’s front desk and immediately asked, “Where’s my mommy?”

“I don’t, I honestly don’t know what to say,” Corbin said later, tears still streaming down her face. “I’m just happy I have him back because it could have been a lot worse.”

A woman who answered the phone at Jeanette’s Little Haven around 9 p.m. Thursday told NBCDFW she had only just learned about the situation, but that she could not comment on what had happened. The woman, who did not want to give her name, said to call back Friday morning.

In an emotional phone call, Jeannette Jones, Jeannette's Little Haven Daycare owner, told NBC 5 that heads will roll" over the mistake.

"I am devastated by this, I admit this was a horrible mistake and I'm so thankful Leonardo is safe," Jones said. "I've been in the child care business 25 years and nothing, nothing, nothing like this has ever happened before"

"This was a shocking mistake and I can promise you heads will roll."

Staff will hold an emergency meeting Saturday morning where 15 employees will be present, Jones said.

In an emotional phone call, Jeannette Jones, Jeannette’s Little Haven Daycare owner, told NBC 5 that heads will roll” over the mistake.

NBC 5's Jeff Smith contributed to this report.