Toronto Zoo officials are investigating after a video surfaced that shows a woman jumping over the first of two fences that separate zoo-goers from Sumatran tigers.

It appears the woman hopped the barrier to retrieve a hat.

The video was posted to YouTube on Saturday. It shows the tiger pacing back and forth, agitated, on the other side of the interior fence.

A representative from the zoo says staff were away from the tiger pen at the time.

Jennifer Tracey says that if a guest at the zoo loses an item near an exhibit, he or she should tell a staff member.

She says that if other guests witness someone jumping over barriers or behaving recklessly, they should also tell zoo staff.

Tracey says that in this case, they weren't notified of the incident until hours later, and they weren't able to find the woman from the video.

But she says she's hoping witnesses will come forward so they can try to figure out what happened.