6-year-old falls from zipline after harness fails in Mexico, and he miraculously walks away

Heart-stopping video out of Mexico showed a 6-year-old boy falling from a zipline after his harness failed.

The boy fell nearly 40 feet but fortunately landed in a lake, so he wasn't seriously hurt.

Video from just prior to the fall showed the zipline slowing and coming to a stop.

The boy's family said he's back at school but is still frightened about what happened.

They're calling for better staff training at the amusement park where the fall happened.