The newborn twins are dead and 14 more babies at this Texas hospital are in critical-but-stable condition after receiving an overdose of the blood-thinning drug Heparin during their stay in the Neonatal Intensive Care Unit.
Small doses of Heparin, an anticoagulant, are routinely used to prevent blood from clotting in patients' I-V lines.
Officials at Christus Spohn in Corpus Christi admit there was a mixing error in this case.
Their investigation into the mishap continues.
"We do not know at this time, what, if any, role the higher than expected concentration of Heparin played in this baby's death," said Dr. Richard Davis, Chief Medical Officer for Christus Spohn Health Systems.
There is no definitive answer about how the Heparin affected Keith Garcia, who died of septic infection.
It's still not clear what killed his twin sister Kay Lynn.
Their case raises new questions about whether this was an accident, or part of a dangerous trend.
Actor Dennis Quaid urged lawmakers on Capitol Hill to hold drug makers responsible and require a barcode medication system for hospitals, after his children nearly died from a heparin overdose last year.
Reasons are hard to come by in Corpus Christi, especially for the family of the Garcia twins.
They will bury their children this Saturday, the same day they had planned to host a baby shower.
Doctors warn the issue with Heparin could be an indication of an even bigger problem.
Studies show one in every 15 children in the hospital is the victim of an accidental overdose, serious drug reaction or medicine mix-up.