Not knowing English can cause all kinds of safety problems for workers, but a recent case in California shows how it may endanger non-workers too.

A six-year-old boy plunged 90 feet (27 meters) to his death from the top of a ferris wheel at a fair in California. His mother believes he panicked and tried to climb out of his seat.

When the mother saw what was happening she screamed at the ride operator to bring her son’s seat back to the ground, but she claims he did not speak English and could not understand what she was saying. After dangling for about 40 seconds, the boy fell.

There were no age restrictions for the ride, but the boy met a height restriction.