The grieving parents of a baby boy killed by a falling lamp post have accused a coroner's court of failing to provide answers about their son's death.
Tommy Hollis suffered a devastating head injury when the lamp post toppled over onto his buggy, which was being pushed by his nanny in Chiswick, west London, on February 23, 2010.
He died in hospital 48 hours later, on the eve of his first birthday.
An inquest jury returned a verdict of accidental death, after deliberating for more than three hours, having been directed to do so by Coroner Elizabeth Pygott.
Ms Pygott had not allowed the jury to deliver a verdict of unlawful killing, despite submissions made by the lawyer representing Tommy's parents Kate and Chris Hollis.
Workman Kelvin Elmore had cut a metal plate supporting the lamp post five days before the accident, thinking it was part of an abandoned tram line, the inquest at West London Coroner's Court heard.
He was attempting to clear underground obstacles so that Virgin Media cables could be moved near Chiswick Town Hall as part of a council road re-widening scheme.
Mr Elmore, of construction firm McNicholas, did not give evidence in person during the three-day inquest after taking legal advice, but in a statement read to the inquest said he wished he could have taken Tommy's place.
Tommy's parents, who also have an eight-month old son, Jack, are now pursuing legal action over the death and say their sorrow was "compounded" by the way the inquest was conducted.
Speaking outside the court, with her husband's arm around her, Mrs Hollis said: "We came here knowing it would be an extremely challenging time for us.
"However, we did not expect our upset and anguish to be compounded by what we feel was the coroner's decision to exclude from consideration questions and evidence that might lead us to better understand how our son, Tommy, was killed in February 2010.
"We feel let down that crucial witnesses were not called or declined to answer questions.
Before the jury began deliberations, Pygott said: "The issue of statutory liability for health and safety matters is not for this court and I do not consider that there is any evidence of a gross error that could give rise to any other conclusion, be it neglect, negligence or indeed unlawful killing. I have discounted this.
"But I should add, for your information, that the fact of an accidental conclusion is not a bar to any prosecution or civil proceedings. It is simply a conclusion limited to this court."
Owain Thomas, representing Tommy's parents Chris and Kate Hollis, had argued to the coroner that the jury should be allowed to return a verdict of unlawful killing.
"In particular, Kelvin Elmore, who cut the plate, chose not to give evidence and explain to the court, in person, why he did what he did.
"Despite what has been reported, Mr Elmore is not an engineer.
"Also, Hounslow Borough Council, under whose control these works were carried out, have been notably absent from these proceedings.
Kate Hollis arrives to hear the verdict at the end of the inquest into the death of her baby son Thomas
"We would also like know why there was no engineer on site at or around the time of the cut to the lamp post when it was apparent that the job was becoming more complicated and how no one realised that the plate was connected to the lamp post despite it being so close."
Mrs Hollis, senior legal counsel at GE Capital, added: "We know that nothing will bring back Tommy but we hope that by continuing to try to find the answers this court failed to find, nothing like it can ever happen again."
Their lawyer Sally Moore, of law firm Leigh Day & Co, said: "We are going to be pursuing those responsible, having reviewed the evidence that has come out of the inquest.
"The family has been greatly disappointed with how the inquest has been conducted. The scope has been narrow to the nth degree. That was not at their request.
"We have tried to have a broad investigation but this coroner was not willing to allow that."
The accident happened when Tommy's nanny was pushing his buggy to a Starbucks coffee shop near Mr and Mrs Hollis's home.
Anna Martin said in a statement that they had been waiting to cross at traffic lights when she heard a "hollow" noise.
"There was a terrible scream and I immediately pulled the pushchair back," she said.
It was then she realised the buggy had no wheels and had been hit by something. The lamp post had broken through the barriers put up by the construction workers.
Ms Martin added: "Tommy looked like he was sleeping. It had all happened so fast."
Tommy was rushed to hospital by air ambulance but brain scans showed his head injuries could not be survived, and his parents agreed that he should not be resuscitated if he suffered a cardiac arrest.
Ms Moore said outside the court: "My clients have been through the most traumatic experience imaginable - the loss of a child is without equal in all our nightmares.
"We will continue to ask the questions we believe were missed by this inquest.
"These include: why, when all involved realised this was no longer a straightforward job, there wasn't a qualified engineer from London Borough of Hounslow coordinating and supervising the works.
"This was their lamppost, their street works outside their town hall."
She added: "How could so many people not realise that the metal plate and lamp post base were not connected?
"The cut to the plate was barely 30cm - the length of a school ruler - from the lamp post base and the plate led directly to it."
The jury of seven men and one woman had heard that Mr Elmore abandoned his attempt to remove the steel plate from the ground when he found he was unable to do so.
Mr Elmore, who was found guilty of gross misconduct by his company and given a written warning, had not come across a similar lamp post support in his career. He is still employed by McNicholas.
Describing the unusual structure as part of their verdict, the jury foreman said: "The foundation of the lamp post was a stepped arrangement, whereby the lamp post entered the ground with a metal plate extending at a 90-degree angle towards the road for approximately 60cm and then welded to a column sunk into the ground."
The lamp post was eventually due to be removed as part of the road widening scheme, designed on behalf of the council by Aecom.
The Health and Safety Executive, which is continuing to investigate Tommy's death, issued a safety alert to the construction industry after the incident.
Ms Pygott said it was not appropriate for her to issue a separate coroner's report, which are written to avoid similar incidents occurring, in this case.
The Hollis family's lawyer said after the inquest concluded that the companies involved had all sought to blame each other.
Ms Moore asked: "Who will accept some responsibility for Tommy's death?
"This week we have seen all parties: London Borough of Hounslow, McNicholas, Virgin Media and Aecom, implicitly or explicitly point the finger of blame at each other."
Mr and Mrs Hollis set up the Tommy Hollis Children's Fund after their baby's death.
A message on the charity's website reads: "Tommy was a happy, smiley boy who spread joy to everyone he met and we would like to do something in his honour to spread the joy he gave us."