TUUSULA, Finland (AP)- An 18-year-old student opened fire in a Finnish high school Wednesday, killing seven students and the principal before turning the gun on himself, police said.The teenager, who was not identified, shot himself in the head but survived for a time. He died at Toolo Hospital, chief doctor Eero Hirvensalo said.The attack at Jokela High School in Tuusula, some 30 miles north of the capital, Helsinki, shocked the Nordic nation, where gun ownership is fairly common by European standards but deadly shootings are rare.Finnish media reported that in 1989 a 14-year-old boy shot and killed two students, apparently for teasing him.Police said at a news conference after the attack that the gunman in Wednesday’s attack shot the victims – five boys, two girls and the female principal – with a .22-caliber pistol. About a dozen other people were injured as they tried to escape the school, police said.”He was from an ordinary family,” police chief Matti Tohkanen said about the gunman, who belonged to a gun club and got a license for the pistol Oct. 19. He did not have a previous criminal record, he said.Finnish media said the shooter revealed his plans in a YouTube posting before the attack.The video, titled “Jokela High School Massacre,” showed a picture of a building by a lake that appeared to be the high school, along with two photos of a young man holding a handgun. The person who posted the video was identified in the user profile as an 18-year-old man from Finland. The posting was later removed.The profile contained a text calling for a “revolution against the system.”Another YouTube video clip showed a young man clad in a dark jacket loading a clip into a handgun and firing several shots at an apple placed on the ground in a forested area. He smiled and waved to the camera at the end of the clip.A third clip showed photos of what appeared to be same man posing with a gun and wearing a T-shirt with the text “Humanity is overrated.”Police said they would investigate any possible connection the gunman might have had to the video.Terhi Vayrynen, 17, a student at the school told The Associated Press that her brother Henri Vayrynen, 13, and his classmates had witnessed the shooting of the principal outside the school through the classroom window.She said the gunman then came into Henri Vayrynen’s class shouting: “Revolution! Smash everything!”When no one did anything, he shot the TV and the windows of the class room but did not fire at the students. The he ran out and down the corridor, Terhi Vayrynen said.Kim Kiuru, a teacher at the school, said the principal announced over the public address system just before noon that all students should remain in their classrooms.”After that I saw the gunman running with what appeared to be a small-caliber handgun in his hand through the doors toward me after which I escaped to the corridor downstairs and ran in the opposite direction,” Kiuru told reporters.Kiuru said he saw a woman’s body as he fled the building.”Then my pupils shouted at me out of the windows to ask what they should do and I told them to jump out of the windows … and all my pupils were saved,” Kiuru said.More than 400 students, from 12 to 18, were enrolled at Jokela, officials said.Prime Minister Matti Vanhanen described the situation as “extremely tragic,” and declared Thursday a day of national mourning with flags to be flown half-staff.