A spokeswoman from the Smithsonian National Zoo in Washington, D.C., has confirmed to ABC News that there was an “incident” near the otters and beavers exhibit this morning.
The area is shut off to the public while DC Fire investigates.
DC Fire and EMS spokesman Timothy Wilson said the cause is not known yet, although there were reports of a chlorine explosion, The Associated Press reported.
More than two million people a year visit the National Zoo, according to its website.
No guests, staff, beavers or otters were hurt in the event.