Summer died in hospital in the early hours of 28 February 2012. She was in the care of her mother Victoria Rogers, stepfather Craig Sharp and maternal grandmother Susan Rogers who were all arrested on suspicion of the infant's murder. However the case was investigated and no-one was ever charged.
Deputy assistant coroner Oliver Longstaff said that there was an overwhelming likelihood that the blow to the head that killed the toddler was non-accidental.
Mr Longstaff concluded: "The unexplained and unresolved death of a 21-month-old child is a matter of legitimate public concern. If the conclusion to this inquest identifies any steps that an appropriate body can take to alleviate that concern, I ask publicly and in the strongest possible terms that those steps should be taken."
"Whatever the state of mind of the perpetrator of the act that caused Summer's ultimately fatal injury, it would have been obvious to that perpetrator that Summer was being subjected to forces far in excess of anything she might have been expected to withstand, and which were overwhelmingly likely to cause her very significant injury."
He added, "The event that led to her death was, I find, an extraordinary and horrific one-off event that could not have been predicted."
Summer's father was represented at the inquest by Marian Cleghorn of GCN, instructed by Lester Morrill incorporating Davies Gore Loma
18th July 2014 Toddler was unlawfully killed by being struck on the head coroner rules The Daily Mail