A worker died after falling into a vat of oily byproduct early Aug. 15 at a facility that converts food waste from the Walt Disney World Resort into biogas.

The 61-year-old man—an employee of Harvest Power in Bay Lake, Fla.,—and a co-worker were emptying an oil or grease byproduct from a tractor-trailer truck into the vat when the man slipped from a grate, according a report from the Orange County Sheriff’s...