National Zoo Panda Gives Birth to Twins

One of the giant panda cubs born at the Smithsonian's National Zoo is being examined by veterinarians, in Washington, DC., Aug. 22, 2015.

One of the giant panda cubs born at the Smithsonian National Zoo is being examined by veterinarians in this image taken in Washington, DC, Aug. 22, 2015.

The National Zoo's giant panda Mei Xiang is shown in this Giant Panda Cam image after giving birth to two cubs, in Washington, DC, Aug. 22, 2015.
 

An artificially inseminated giant panda took U.S. zoo officials by surprise on August 22, 2015 when she gave birth to twins - more than four hours apart, at the National Zoo, Washington, D.C.

In this photo provided by the Smithsonian National Zoo, one of the giant panda cubs is examined by veterinarians after being born at the zoo on Aug. 22, 2015, in Washington. (Pamela Baker-Masson/Smithsonian's National Zoo)