HOUSTON — Visitors at the Houston Zoo were evacuated from the ape habitat Monday morning after a chimpanzee broke the interior pane of a protective glass window.

One visitor described a “sonic boom” sound then saw the apes running.

A zoo spokeswoman says nobody was in danger and the glass on the exterior and interior of the enclosure did not shatter, only the middle layer.

The ape habitat has reopened without the animals for the day. The chimpanzees will be held in their boarding area outside of public view for the remainder of the day so the window can be repaired.