An ambulance first was sent to the school at 8:21 a.m. when a child was reported to be in distress, according to the San Juan County Sheriff's Department. An hour later, an adult at the school was reported to have collapsed. By 9:40, calls were coming in for multiple patients at the school who were dizzy and sick.
"Some of the younger kids were very confused, seeing victims on the ground," Bailey said.
The exhaust system of a propane-fueled water heater in the school was the likely source of the carbon monoxide fumes, said Clayton Holt, school district business administrator. An exhaust pipe coming from one of two water heaters had become disconnected at some time venting gas into a mechanical room, the kitchen, and classrooms, according to the sheriff's department. The school had no carbon monoxide alarms, Holt said; they are not required by safety code, and generally are not considered standard for commercial buildings, including schools.
Paramedics, law enforcement and rescue crews rushed to the school from several southeastern Utah agencies, along with some responders from Colorado and Arizona. One student and two adults were flown to hospitals. As of Monday night, all patients were reported to have recovered except for an EMT who was injured in the response and a teacher the most critically-poisoned patient who was being flown to Salt Lake City for treatment in a hyperbaric chamber, Bailey said.
As medics removed affected patients, the remainder of the estimated 280 students and staff were evacuated to nearby White Horse High School. Some students were taken by parents to area clinics to be checked out, but the rest spent the remainder of the school day at the high school until being picked up by parents or buses, Holt said.
Shawna Hamm, who lives in Aneth, a town about 8 miles southeast of Montezuma Creek, said she saw a helicopter fly past her house, as well as two Navajo Nation police officers with lights and sirens.
Earlier, she had received a text message from her sister-in-law, a cook at the elementary school, saying that there had been a gas leak and she was feeling dizzy. "She wasn't feeling good."
Hamm's nephew, a student at the school, also complained of dizziness.
While other people were being air-lifted to the hospital, her nephew's father picked him up and brought him home, where he seemed to be doing fine, Hamm said.
She said her sister-in-law, who is about three months pregnant, got a ride to a hospital in Blanding to get checked out.
Officials said the school is expected to be open Tuesday, with all classes taking place. Temporary carbon monoxide detectors have been installed at the school, and the district is looking to install permanent devices in all 12 schools.
"Given a situation like this, how it could have been helped by detectors, I'm sure it would be in our best interest to do that," Wright said.
Montezuma Creek is located about 10 miles east of Bluff.