A faulty wave machine at a popular summer water park attraction in Jilin Province, China caused a 10-foot “tsunami” that swept away dozens of pool-goers.

The incident, which left 44 people injured, took place at the Yulong Shuiyun Water Amusement Park in the city of Longjing on Sunday, reports the South China Morning Post.

Investigators say the machine for the wave pool malfunctioned and generated a powerful wave that hurled swimmers into each other and out of the pool.