Zoo officials wait for cause of baby panda's death

WASHINGTON -- National Zoo officials waited yesterday for word on why a 6-day-old panda cub died and lamented a heartbreaking setback to their breeding program.

The cub had liver abnormalities and fluid in its abdomen, but cause of death will not be known until full necropsy results are available, within two weeks.

The cub, believed to be female, died Sunday, less than a week after its birth surprised and delighted zoo officials and visitors. Zookeepers had all but given up on the chances of Mei Xiang, the mother, conceiving after six years of failed attempts.

This much is known: The cub appeared in good condition and had been drinking its mother's milk. It wasn't crushed to death by its mother, which has happened accidentally to other cubs in captivity. At birth, a cub is hairless, its eyes are closed and it is about the size of a stick of butter. Their mothers weigh about 1,000 times more. -- AP