Abstract: At 9:06 a.m. on September 28, 2021, Employee # 1 was operating a riding mower on a hill close to a retention pond. The grassy embankment surrounding the pond has slopes with varying degree angles (between 15 and 30 degrees). At one point the lawn mower rolled off the hill while Employee # 1 was operating it. The mower landed in the retention pond, pinning Employee # 1 under the water. There were no witnesses to the incident. Employee # 1 was found by two other coworkers in the pond along with the lawn mower. Although the lawn mower was equipped with roll over protection, it was not in use at the time of the incident. Employee # 1 drowned in the retention pond. Employee # 1 was trapped under the lawn mower after it fell into the pond. He was killed by drowning.