Over 50 people were injured after a Delta flight that was returning to Los Angeles International Airport on Tuesday dumped fuel on and near four schools, the Los Angeles Times reports. A Delta spokesperson said Flight 89, en route to Shanghai, had started experiencing an “an engine issue” after takeoff that required the plane to return to LAX. “The aircraft landed safely after an emergency fuel release to reduce landing weight,” the spokesperson said. The Los Angeles Fire Department told The Daily Beast that 70 firefighters and paramedics responded to Park Avenue Elementary School at around noon on Tuesday. According to an L.A. Fire Department spokesperson, “two classes were outside when the liquid came down” and school staff and students were “instructed to go indoors” shortly thereafter. The fire department later tweeted that a total of 44 people from four schools sustained minor injuries from the incident—including 20 children and 11 adults at Park Avenue Elementary, six at Tweedy Elementary, six at San Gabriel Elementary, and one adult at Graham Elementary. According to the Associated Press, 56 total injuries were reported, and those who experienced skin irritation were treated with soap and water.