OSLO, Norway (AP) — Police arrived at an island massacre about 1.5 hours after a gunman first opened fire, slowed because they didn't have quick access to a helicopter and then couldn't find a boat to make their way to the scene just several hundred yards offshore. The assailant surrendered when police finally reached him, but 82 people died before that.Survivors of the shooting spree have described hiding and fleeing into the water to escape the gunman, but a police briefing Saturday detailed for the first time how long the terror lasted — and how long victims waited for help.The shooting came on the heels of what police told The Associated Press was an “Oklahoma city-type” bombing in Oslo's downtown: It targeted a government building, was allegedly perpetrated by a homegrown assailant and used the same mix of fertilizer and fuel that blew up a federal building in the U.S. in 1995.In all, at least 92 people were killed in the twin attacks that police are blaming on the same suspect, 32-year-old Norwegian Anders Behring Breivik.A SWAT team was dispatched to the island more than 50 minutes after people vacationing at a campground said they heard shooting across the lake, according to Police Chief Sveinung Sponheim. The drive to the lake took about 20 minutes, and once there, the team took another 20 minutes to find a boat.Footage filmed from a helicopter that showed the gunman firing into the water added to the impression that police were slow to the scene.