(CNN) Sixty people were treated after a plane dumped jet fuel while returning to the Los Angeles International Airport on Tuesday, hitting five elementary schools and one high school.

The incident happened just after noon Tuesday, inspector Sean Ferguson of the Los Angeles County Fire Department told CNN. The most heavily affected school was Park Avenue Elementary in Cudahy, where 20 children and 11 adults reported minor injuries. The school is about 19 miles east of the airport.

The other schools affected were San Gabriel Elementary, Graham Elementary, Tweedy Elementary, 93rd Street Elementary and Jordan High School.

After checking all of the affected schools later Tuesday, hazardous materials experts said there was no more danger, fire department officials said. All schools will be open and operating on their normal schedules Wednesday.

"With the monitoring devices that we have, there are no explosive limits that are being detected at all, as well as solid or liquid products remaining," Battalion Chief Jason Robertson said in a news conference, adding that the fire department believes all of the jet fuel has evaporated.

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