Smaller of two panda cubs at National Zoo has died

The National Zoo is reporting that the smaller of two panda cubs born Saturday night has died.

The zoo announced the news on Twitter Wednesday afternoon.

In a press conference held over Periscope at 4pm, the zoo explained that they would regularly swap the cubs out between an incubator, and spending time with Mei Xiang, their mom. When they switched the cubs out this morning they noticed the smaller cub had not gained any weight, seemed weaker, and was possibly having respiratory problems. Despite keepers administering antibiotics and providing respiratory support, the cub’s condition continually declined, until it passed away.

The cubs were born Saturday evening, one cub at 5:35 p.m. EDT and the other at 10:07 pm. Zoo keepers began switching the cubs out when they noticed that Mei Xiang did not seem to be able to care for both cubs at the same time. This was only the third pair of panda cub twins born in captivity, and keepers have repeatedly stressed that the cubs are in a “high risk” period.

Keepers have reported that the other cub was still doing well — eating, drinking, and defecating normally without signs of respiratory distress.