OKLAHOMA CITY -- Oklahoma City Public Schools (OKCPS) said the three students and three staff members at Lee Elementary who were hospitalized Monday are now doing well; a day after becoming sick from carbon monoxide poisoning.
The school had to be evacuated Monday and classes were canceled for Tuesday.
Classes will resume Wednesday.
An OKCPS official says a faulty heating unit is to blame for the carbon monoxide leak and they're now testing it to find the problem.
Crews spent the entire day installing a new unit on the school's roof.
Terry Wolfe, the OKCPS Sr. Facilities Officer, said those heating units normally last 12 to 15 years, but this one is only four years old.
He said the district checks those units every month and they are inspected before the schools turn on the heat.
OKCPS does not require carbon monoxide detectors in their schools and Lee Elementary had none.
NewsChannel 4 asked Wolfe - why?
"That's a fine question," he said. "We're going to implement a program where we can get that implemented through our district.
"We're still trying to investigate what the cause (of the CO leak) was. Of course, extremely concerned for (the victims') welfare and very proud of the way the school handled things."
The State Superintendent's office said local districts should decide if, and how many, CO detectors they should have.
Edmond says half their schools have them.
We're told Moore, Mid-Del and Norman do not have detectors because they perform regular inspections on heating units.