Conjoined twin boys who shared a heart, torso and limbs died just a day after being born at an Atlanta hospital, their grieving parents said in a video posted to Facebook.

Asa and Eli Hamby died at the Children's Healthcare of Atlanta at Egleston where they had been transferred following their birth on Dec. 4 at the city's Northside Hospital.

"I am so sad to say that my sons passed away today at 5 o'clock," Michael Hamby said in an emotional Facebook video that he and his wife Robin Hamby posted late on Dec. 5. "They fought long and hard."

The twins began experiencing issues with their shared heart early Friday, doctors said, with their heart rate uncontrollably rising to as high as 300 beats per minute.

Medicines administered to the twins were unable to control the runaway heartbeats, even though "[doctors] did everything they could possibly do for them," Robin said.

"They took them off the ventilators and about 45 minutes later they went to sleep to be with the Lord," recalled Michael in the video.

Michael and Robin from Alabama had chronicled the difficult pregnancy on Facebook, posting videos and updates that had garnered thousands of supporters.

The twins were delivered by Caesarean section at 37 weeks into the pregnancy.

Conjoined twins, occurring about once in every 200,000 live births, face daunting odds of survival, with 40 to 60 percent stillborn.

Of those that do survive birth, around 35 percent do not survive beyond a few days.

The Hambys and their doctors had been aware of the difficulties the twins would face. Extensive testing and ultrasound showed the babies had a condition called dicephalic parapagus: they were joined on the side. This extremely rare form of conjoined twins is seen in one in a million births.

The twins together weighed 9 pounds, 10 ounces at birth.

Because they shared a heart and a circulatory system, doctors said that even if they had lived, it would have been impossible to separate them.

In the video, Robin thanked the more than 4,000 "friends" following their Facebook page.

"You all supported us, loved us, prayed for us," she said. "Because of your prayers, we had additional blessings and miracles."

"They looked so much like Michael," she said of the twins. "They were just the cutest little things. So, so sweet."