The boys were in the water more than 20 minutes after the first 999 calls, the inquest hears.
Four boys who fell into an icy lake last week died from drowning, an inquest has heard.
Finlay Butler, eight, and his younger brother Samuel, six, died, as did their cousin Thomas Stewart, 11, and another boy, Jack Johnson, 10.
They were pulled from water at Babbs Mill Park, near Solihull, in the West Midlands, on 11 December.
The boys were in the water more than 20 minutes after the first 999 calls, the inquest heard.
Three of them were pulled out of the water 22 minutes afterwards, while the fourth boy was pulled out nine minutes later.
Stories emerged last week of police officers attempting to punch through ice in a bid to reach them.
Det Insp Jim Edmonds told the inquest there were “heroic efforts” by the emergency services to save the boys.
He told Birmingham and Solihull Coroner’s Court police received a series of calls from the public.
Birmingham and Solihull Coroner Louise Hunt offered her sincere condolences to the families and said it was a “devastating tragedy”.
She said it was difficult to comprehend the pain and grief the families were experiencing.
The hearing was adjourned and a full inquest into all four deaths will take place in July.
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