Zawadi enters the display area through a door that slides upward to open and apparently did not notice when the door began to close behind him.
The lion's tail ends up pinched under the door, leading him to roar and quickly pull away.
Zawadi's tail appears to be bleeding toward the end of the video, but zookeepers said the injury was minor and he is recovering.
"It doesn't appear to be a serious injury, and we're glad that Zawadi seems to be recovering well. But you always feel badly when an animal you care for is hurt," animal curator Michael Illig said. "We'll be reviewing all the details of the situation -- from the building to the mechanics to our protocols -- in order to make sure this cannot happen again."
