SAND SPRINGS, Oklahoma - Officials with Sand Springs public schools said their focus this week has been to ensure the building is safe and to get school started up again which they did when the bells rang Friday morning at 8:30.

School officials released a statement saying there are now Carbon Monoxide detectors in all of the classrooms at Clyde Boyd Middle school. They added that they have plans to install detectors in every classroom in the district by winter break.

School let out early on Monday when officials realized that students were getting sick from a carbon monoxide leak.

"Well, I was pretty scared especially when they said to evacuate, and I was very confused. I was confused and not knowing what was going on at all," said 6th grader Kennedy Shirley.

Officials said the issue started with a faulty heater and many of the heaters in the building have been replaced or repaired. News On 6 has learned from speaking with area hospitals and poison control that more than 80 students were treated for symptoms related to the leak.

The school calendar has built-in days for emergencies, so students will not have to make up the days they have missed.