A list of each death and what/who caused them. Also shown is the amount of minutes through the film in which the deaths took place. (Huge spoilers ahead)
0:12 Fumiyo Fujioshi (girl #12) - Knife thrown at head by Kitano.
0:14 Yoshitoki Kuninobu (boy #7) - Collar activated by Kitano.
0:21 Mayumi Tendou (girl #14) - Shot through the neck with crossbow by Yoshio Akamatsu.
0:22 Yoshio Akamatsu (boy #1) - Shot through the heart with his own crossbow by Kazushi Niida.
0:27 Hiroshi Kuronaga (boy #9), Ryuhei Sasagawa (boy #10), Mitsuru Numai (boy #17), Shou Tsukioka (boy #14), Izumi Kanai (girl #5) - All shot with Uzi 9mm by Kazuo Kiriyama.
0:29 Sakura Ogawa (girl #4) and Kazuhiko Yamamoto (boy #21) - Commit suicide together by jumping off a cliff.
0:31 Yoji Kuramoto (boy #8) and Yoshimi Yahagi (girl #21) - Commit suicide together by hanging.
0:31 Megumi Eto (girl #3) - Throat slit with a kama by Mitsuko Soma.
0:34 Tatsumichi Oki (boy #3) - Accidentally killed by Shuya Nanahara with his own hand-axe through his head.
0:35 Kyouichi Motobuchi (boy #20) - Shot by Shogo Kawada with SPAS 12 Pump Action shotgun.
0:36 Yumiko Kusaka (girl #7) and Yukiko Kitano (girl #6) - Shot with Uzi 9mm by Kazuo Kiriyama.
0:41 Hirono Shimizu (girl #10) - Shot in the back twice with Colt .45 pistol by Mitsuko Soma.
0:49 Kazushi Niida (boy #16) - Stabbed several times in the back, groin and heart with a jackknife by Takako Chigusa.
0:52 Takako Chigusa (girl #13) - Shot multiple times with Colt .45 pistol by Mitsuko Soma, dies several minutes later.
1:00 Toshinori Oda (boy #4) - Decapitated by Kazuo Kiriyama with a wakizashi (a short sword used by samurai; not to be confused with the longer katana).
1:05 Kaori Minami (girl #20) and Mizuho Inada (girl #1) - Kaori Minami stabbed in the stomach with a knife, Mizuho Inada stabbed in the side with a pick-axe. (Killed each other fighting over a life preserver.)
1:05 Yuuichirou Takiguchi (boy #13) and Tadakatsu Hatagami (boy #18) - Seen naked, stabbed to death by Mitsuko Soma; she is dressing herself, so presumably she seduced them to lower their guard. (Possibly castrated, as well. A lot of blood near their groins.)
1:10 Yuka Nakagawa (girl #16) - Accidentally poisoned with potassium cyanide by Yuko Sakaki after eating soup meant for Shuya Nanahara.
1:11 Yukie Utsumi (girl #2), Satomi Noda (girl #17), Haruka Tanizawa (girl #12), Chisato Matsui (girl #19) - All killed in a gunfight after Yuka Nakagawa is poisoned. (Satomi Noda shoots Chisato Matsui, Haruka Tanizawa and Yukie Utsumi with a Mini Uzi, and is then shot with a Smith & Wesson .357 by Yukie Utsumi before she also dies from her wounds).
1:11 Yuko Sakaki (girl #9) - Commits suicide by jumping from lighthouse onto rocks after causing the death of 5 of her classmates.
1:24 Hiroki Sugimura (boy #11) - Shot 6 times with Glock 17 pistol by Kayoko Kotohiki.
1:24 Kayoko Kotohiki (girl #8) - Shot through the heart with Colt .45 pistol by Mitsuko Soma.
1:26 Mitsuko Soma (girl #11) - Shot multiple times with Uzi 9mm, and then finished off with 4 bullets from a Colt .357 Revolver by Kazuo Kiriyama.
1:30 Keita Iijima (boy #2), Yutaka Seto (boy #12) - Shot multiple times with Uzi 9mm by Kazuo Kiriyama.
1:30 Shinji Mimura (boy #19) - Sacrifices himself by blowing up the bomb he, Yutaka and Keita had made in the hopes of at least taking Kazuo Kiriyama out of the competition. (Shot multiple times by Kazuo Kiriyama, would have succombed to the wounds, had he not blown himself up.)
1:31 Kazuo Kiriyama (boy #6) - Shot in the collar(causing it to explode) by Shogo Kawada.
1:40 Shogo Kawada (boy #5) - Dies from wounds received in his gunfight with Kazuo Kiriyama.
Noriko Nakagawa (girl #15) and Shuya Nanahara (boy #15) survive.