(CNN)Few people share as much in life as conjoined twins. For Maria and Consolata Mwakikuti, conjoined twins and orphans from Tanzania, this was certainly the case.
But at 2:30 p.m. local time on Saturday, Maria passed away. Fifteen minutes later, so, too, did Consolata.
The twins were conjoined at their abdomen and shared organs such as the stomach and part of the aorta, a crucial artery that runs from the heart down to the abdomen. They had separate heads and hearts.
Early investigations soon after their birth confirmed the two sisters could not be separated, said Dr. Faith Kundy, a physician at Iringa Regional Hospital, where the women died.
In December, Maria was diagnosed with a respiratory problem resulting from an inoperable chest deformity, the ultimate cause of her death, Kundy told CNN.
"They underwent tests and it was very unfortunate that nothing could be done," said Kundy, who was with the twins during their last few days. "It was very sad for me. Apart from being patients they were friends, they were funny people. I feel so sad because they had a hope of living."
But Kundy added it was a major achievement that the twins reached age 21.
Maria and Consolata were taken care of by a congregation of nuns, the Consolata Sisters, and were born at the Consolata Regional Hospital, where their parents left them after birth, according to Sister Jane Nugi.