Two premature babies died within weeks of each other after neglect by a hospital, an inquest jury has found.

Westminster Coroners’ Court heard Elena Ali and Sunny Parker-Propst were both given sodium nitrite instead of sodium bicarbonate in 2020 while under the care of staff at Chelsea and Westminster Hospital.

On Monday they returned verdicts of unlawful killing contributed to by neglect for baby Sunny, and accidental death contributed to by neglect for baby Elena.

Lesley Watts, chief executive of Chelsea and Westminster Hospital NHS Foundation Trust, said: “We apologise unreservedly for the failings in care provided to Elena and Sunny.”

Ms Watts added: “We took immediate action to put measures in place to prevent such tragic incidents from happening again.”

The ten-day inquest was held by the senior coroner for Inner West London, Prof Fiona Wilcox.

Elena Ali was born prematurely on 16 April 2020 and her condition was classed as moderate.

Two days later, routine monitoring revealed she had too much acid in her blood, known as metabolic acidosis.

She was prescribed a sodium bicarbonate infusion, but was instead given a sodium nitrite infusion.

She died that day.

Sunny Parker-Propst was born prematurely two weeks later, on 30 April, and was transferred to the neonatal intensive care unit (NICU) for continuing care.

He was also prescribed a sodium bicarbonate infusion due to metabolic acidosis, but was given a sodium nitrite infusion in error after it was wrongly stocked on the NICU and selected and administered by nursing staff.

He died on 9 May.

The coroner said the hospital’s chief pharmacist admitted there had been a “complete and total” failure in checks within the pharmacy, which led to a box of sodium nitrite being issued instead of sodium bicarbonate.

Internal investigations within the pharmacy failed to identify who had issued the wrong drug, the inquest was told.

The unit’s neonatal nurse coordinator told the inquest she knew about a policy to check vials by picking them up and looking at them at eye level – but that she did not do this.

She accepted that if she had done so, she would have been able to see it was in fact sodium nitrite.

Elena’s mother Selena Ali said: “It was so shocking when Elena first died, we were told she died cause of extreme prematurity.

“It was only 13 days later we got a call from the chief nurse to say, ‘we’ve got bad news, there was a medication error’.”

Sunny’s mother Kerstin Propst says she couldn’t believe this could happen to two babies.

“It’s shocking – especially a big hospital like that, especially twice, it makes you think how many more things happen that people are not aware of.”

The families’ solicitor Frankie Rhodes said the verdict would hopefully give “some closure” to the families after four years, but highlighted a “catalogue of errors and basic failings from the nurses involved in both babies’ care”.

“It is shocking that these premature babies, some of the most vulnerable in society, were put at risk – and both Elena and Sunny needlessly lost their lives due to failures to do simple checks which are a fundamental part of a neonatal nurses’ job,” she said.