Premature twins born at the scandal-hit Stafford Hospital died after receiving an overdose of morphine administered in error, a disciplinary hearing has been told.
The babies, who were born at 27 weeks, named only as twin one and twin two, received 600 and 850 microgrammes of morphine respectively when they should have been given between 50 and 100 microgrammes, a Nursing and Midwifery Council hearing was told.
Joanne Thompson, a senior staff nurse in the special care baby unit of the hospital, is accused of allowing a more junior nurse, Lisa Lucas, prepare for the administration and/or administer the drug to the twins with the help of a junior doctor, against hospital protocol which states this should be carried out by two registered nurses.
Hayley Amos, a neonatal senior staff nurse at the hospital at the time, said she had reported for duty on the 7am shift on October 30 2010 after the overdose had been administered.
Speaking about the reaction of the two nurses after the error had been discovered, she said: "Joanne went very quiet at this point and was visibly shocked. Lisa was hysterical and kept saying, 'Oh my God, what if I have killed these babies?' and she was crying and shaking.
"I did my best to calm and reassure Lisa by saying, 'look at them Lisa, they are fine, now calm down'. I don't recall Joanne saying anything."
Ms Amos added later: "It appears unfair that only Lisa appears to have been held accountable by the trust for this drug error. As the nurse in charge Joanne should have ensured that the hospital policy was adhered to and clear instructions and supervision was given to the more junior nurse.
"A controlled drug error had taken place and Joanne should take some responsibility."
Mrs Thompson denies a series of charges including failing to take the clinical lead of nursing care when required in relation to the administration of the morphine to the babies.
An inquest into the deaths of the twins, Alfie and Harry McQuillan, who died on November 1, 2010, heard that they were given an "excessive" dose of morphine hours after their birth at Stafford Hospital.
Access Legal from Shoosmiths - the law firm representing the twins' parents - said last May that South Staffordshire Coroner Andrew Haigh had described the babies' treatment after birth as "suboptimal", adding that "there were failings in the care the twins received".
A spokesman for the company said the coroner, who recorded a narrative verdict at Cannock Coroner's Court, said the boys died from complications of extreme prematurity and that morphine was "likely to have played a role".
The hearing comes after the Francis inquiry into failings at Stafford Hospital where it is estimated there were between 400 and 1,200 excess deaths between 2005 and 2009.