Keeping the Lions Friendly Was Not the Only Production Obstacle
The production team was hit with many obstacles during the filming process. When almost 80 percent of all scenes had been completed, a 10-foot-high wave of water hit the premises. Thousands of tons of liquid submerged the compound; the first floor was ridden with mud, and a lot was destroyed.
Source: IMDB
The editing bay was wiped out, and the water also took out a lot of the plantation. Cages and walls collapsed, allowing a lot of the animals to escape. The jailbreakers included Robbie, who was the star of the film; the only gentle giant. Robbie tragically ended up getting killed by the Sherriff Department. So much for being gentle.