7 puppies die on O'Hare-bound flight

American Airlines officials are trying to determine the cause of death for seven puppies that died after landing at O'Hare International Airport Tuesday morning.

Officials said the puppies were alive when American Airlines Flight 851 landed at O'Hare from Tulsa, Okla., at about 9 a.m. Tuesday morning.

After landing, however, seven of the puppies died at some point before being loaded onto a connecting flight, said Mary Frances Fagan, a spokeswoman for the airline.

She said it remains unclear if there were 14 or 15 puppies on the flight from Tulsa, which took off from Oklahoma at 7:30 a.m.

Fagan said the airline is conducting an internal investigation to determine how the puppies died.

"What exactly happened is still being investigated," she said. "American Airlines is still talking with the employees to try and understand what happened."