Atlanta Public Schools superintendent Erroll Davis said Thursday that the carbon monoxide leak Monday at Finch Elementary School in Atlanta that poisoned some 40 students and 10 adults was caused by two maintenance workers. Davis says the workers failed to reopen a valve on the school furnace after inspecting it last Friday.
Students and teachers began fainting on Monday at Finch and APS discovered the mistake after looking at school videotapes on Wednesday of the workers performing maintenance on the furnace the previous Friday.
Davis said that were it not for the investigation the district would not have found the source of the leak.
"Neither of these two individuals came forward," he said at a news conference. "To say that is a disappointment is an understatement. We have now launched a full investigation of that."
The entire school was evacuated and approximately 500 children were checked for illness at a local hospital. The most common symptoms of carbon monoxide poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain and confusion. In extreme circumstances carbon monoxide poisoning can be fatal.
Gas levels peaked inside the school peaked at 1,700 parts per million, the highest fire officials "had ever seen," according to fire department spokeswoman AFD Capt. Marian McDaniel.
"The highest levels were near the furnace, but they were high throughout the school," McDaniel told ABC News.com Monday.
The district declined to name the employees, or say what if any action would be taken against them.
Students at Finch have been attending classes at Kennedy Middle School since the carbon monoxide leak. APS officials said they expect Finch to reopen Friday since a temporary boiler has been installed and passed tests. The district is awaiting an official permit from the Atlanta Fire Department.
Many parents have been keeping their children home from school since the incident, saying they had no intention of sending them to school no matter where classes were held.
Finch Elementary School is located in Southwest Atlanta and is 99 percent Black, with 1 percent being "dual race," according to the PublicSchoolsK12.com. The site also reports that 94 percent of the student at Finch are eligible for free lunch. The AJC reports that the school does not have carbon monoxide detectors and the state does not require them.