Nine Visalia fifth-graders were taken by ambulance to a hospital Friday after they drank a concentrated fruit-flavored liquid that's supposed to be diluted in water and became ill.
None needed to be hospitalized and all were released to their parents that afternoon, Visalia Unified area Superintendent Doug Bartsch said.
Ambulances and fire trucks swarmed Mountain View Elementary School as firefighters, school nurses and administrators tried to figure out what happened.
At least one student -- and probably more -- drank undiluted Mio brand water enhancer at lunch, reportedly by spreading it on their hands and licking it, Bartsch said.
The illnesses began about 2 p.m. at the school in southeast Visalia when a girl in a fifth-grade class "abruptly left the classroom," Bartsch said.
The substitute teacher checked where the girl was sitting for clues.
"It smelled like vomit, but he didn't see any," Bartsch said.
Soon other students said they were feeling sick and went to the front office for help. "A chain reaction started" and seven students vomited, he said.
"At first, we didn't know what we had," Bartsch said.
Someone called the district nurse, who said to call 911. The Visalia Fire Department's hazardous materials team was sent to investigate.
In all, 10 students from one fifth-grade class became ill, and nine went to the hospital. The other was picked up by her grandfather, Bartsch said.
Also, four students from a fourth-grade class said they felt sick but did not consume the water enhancer and were well enough to go home with their parents.
Some students left campus in tears when school let out around 3 p.m.
They included Annamarie Rangel, 10, a fifth-grader who said she heard students from another class throwing up in a bathroom next to her classroom. "It sounded like they were sick for a month," she said.
Fifth-grader Andrew Harris, 10, a student in the affected classroom, said a classmate suddenly "ran outside and started throwing up."
After that, "the smell was strong," he said. Harris said he didn't drink the liquid and never felt sick.
The fire department told school officials that "a combination of factors" led to the mass vomiting, Bartsch said. The undiluted Mio made at least one of the students sick and the smell in the classroom made others nauseous -- and maybe both were at play, he said.
This was the first incident involving a water enhancer liquid at a Visalia school, and administrators will discuss whether a warning needs to be issued to students, parents or teachers, he said.
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