The Myyrmanni bombing took place on October 11, 2002, in Myyrmäki, Vantaa, Finland, in Greater Helsinki, at the Myyrmanni shopping mall. A bomb was hidden in a backpack, which exploded in the central square of the shopping center on top of a metal waste container, located in the center of the square, at 19:36. Five people were instantly killed, including the bomber. The waste container was shattered, and fragments of the structure increased the amount of shrapnel and the devastation. The explosion ruined 400 m of the shopping center, carved a 10-cm deep crater in the floor where the waste container had stood and blew the glass dome over the square up and outwards from the mall. In total seven died, including two teenagers and a seven-year-old. 159 were injured, including 10 children. 66 victims required hospitalization with the remainder treated and released at the scene. The bombing took place during the pre-weekend shopping surge late on a Friday afternoon, with 1,000–2,000 people in the shopping center, including many children who had come to see a clown performance.

The bomb carrier was Petri Erkki Tapio Gerdt (April 17, 1983 – October 11, 2002), a 19-year-old chemical engineering student at the Espoo-Vantaa Institute of Technology (EVTEK). Described as quiet and somewhat withdrawn, Gerdt was an amateur bomb-maker with no known close friends. He participated in basketball and had no prior criminal record. Gerdt died in the explosion he caused. He was also an active member of Kotikemia (lit. "home chemistry"), an online forum for amateur chemists. The moderator of Kotikemia was acquitted of responsibility in court. The explosive device was likely constructed in Gerdt's apartment. It was a 1.5 liter plastic bottle that contained ammonium nitrate and nitromethane with shotgun pellets and weighed about 2–3 kilograms (4.4–6.6 lb). Investigations revealed that some kind of timer was also used. Kotikemia was shut down by the authorities following the bombing.

The Finnish National Bureau of Investigation investigated the event as six accounts of murder, one account of aggravated criminal mischief and one account of an explosives offence. The case was closed in January 2003 without any indictments as Gerdt was the sole suspect. Gerdt's motive for the bombing was not ascertained during the investigation. There was no evidence found that Gerdt had links to any outside groups or to any international terrorist organizations.

On October 15, 2002, Finland observed a national day of mourning in response to the tragic events. Government buildings were closed, a moment of silence was observed in Parliament, and flags across the country were flown at half-staff to honor the victims. The shopping center was closed for repairs for nearly three weeks before re-opening later in October.

The bombing was especially shocking for Finland and the other Nordic countries, where these type of attacks are extremely rare.

Petri Gerdt's father, Armas, wrote the book Petrin matka Myyrmanniin (Petri's Road to Myyrmanni) about the incident.

• Petrin matka Myyrmanniin, Suomalainen.com bookstore

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