The Norwegian police have defended the time it took for them to respond to initial reports of the shooting on Utoeya.
No helicopter was available so the special firearms unit had to make the 45 kilometre journey from Oslo by car.
The police boat at the shore was too small to take them and began to leak. They then had to commandeer recreational boats to cross.
The police have revised down their estimate of the time it took to get to Utoya, from 90 minutes to 60.
The exact duration might be disputed, but what it does mean is that the gunman had at least one hour to go about his deadly work unchallenged.
Hundreds of people, many of them teenagers, fled around the island to hide or jumped into the surrounding Tyrifjord in a bid to escape.