Question: The event "Bloody Wednesday" is based on took place in what year?

Context articles: WWE Elimination Chamber
Aniversario: Never Compromise
MoSo
Vengeance (2011)
Bloody Wednesday (Poland)
Bloody Wednesday (film)
1920 Nebi Musa riots
Night of Champions (2013)
San Ysidro McDonald's massacre
Battle of the Viaduct

Elimination Chamber is a professional wrestling pay-per-view (PPV) event, produced by WWE, a professional wrestling promotion based in Connecticut.
 The event was created in 2010, with its inaugural event taking place on February 21, 2010, replacing No Way Out.
 Elimination Chamber is a pay-per-view (PPV) event consisting of a main event and undercard that features championship matches and other various matches.
 The concept of the show was that the two main event matches were contested inside the Elimination Chamber; one of these matches typically featured the WWE Championship being defended, while the other was usually contested for the World Heavyweight Championship (the two titles were unified in December 2013).
 The first Elimination Chamber event took place on February 21, 2010 and aired live on PPV.
 The event's name was selected after WWE allowed fans to provide input via a survey on their official website and was chosen over Heavy Metal, Battle Chamber, Chamber of Conflict, and the original No Way Out name.
 Since its origin, each event has been held in an indoor arena, with all five taking place in the United States.
 In 2015, the event was replaced by Fastlane in the February pay-per-view slot.
 However, the 2015 event was later announced to be streamed exclusively on the WWE Network in the United States on May 31 and was also available on PPV elsewhere.
 WWE also confirmed that the newly vacant WWE Intercontinental Championship was being decided inside the Elimination Chamber.
 The event did not occur in 2016, but returned in 2017 as a SmackDown branded event.
Aniversario: Never Compromise was a professional wrestling internet pay-per-view (iPPV) event produced by the Chikara promotion, that took place on June 2, 2013, at the Trocadero Theatre in Philadelphia, Pennsylvania.
 The event marked Chikara's fourth iPPV, third to take place at the Trocadero Theatre and the promotion's only event to take place in Philadelphia in 2013.
 Much like the previous iPPV, Under the Hood, Aniversario: Never Compromise also aired through Smart Mark Video.
 Aniversario: Never Compromise celebrated Chikara's eleventh anniversary and was the first anniversary event to take place on iPPV; in the past, the promotion had celebrated its anniversaries with weekends of two shows.
 The event saw all three Chikara championships being defended with one title change, where Pieces of Hate (Jigsaw and The Shard) defeated 3.0 (Scott Parker and Shane Matthews) for the Campeonatos de Parejas.
 Another major match during the event saw former Campeones de Parejas, Amasis and Ophidian, end their nineteen-month storyline rivalry in a Sarcophagus match.
 The event concluded with a major storyline development, where Chikara's authority figure Wink Vavasseur ended the event and shut down the promotion, while the main event was still going on in the ring, leading to the promotion going inactive for a full year.
MoSo was a music and technology event that has been held annually in Saskatoon, Saskatchewan in Canada that first began in 2011 and held its final event in 2016.
 It was divided into two parts held concurrently: a technology conference known as MoSo Conf (the name MoSo is derived from the term "Mobile Social"), and a music festival known as MoSo Fest.
 Technology-related sessions took place during the day Thursday to Saturday; musical performances generally took place at night from Wednesday to Sunday, although a daytime outdoor stage was added in 2014 accompanied by several food carts.
 The event typically took place in the second or third week of June.
Vengeance (2011) was a professional wrestling pay-per-view (PPV) event produced by WWE that took place on October 23, 2011 at the AT&T Center in San Antonio, Texas.
 It is the twelfth event under the Vengeance/Night of Champions chronology and the first event under the Vengeance name since the .
 Eight matches took place at the event.
 The pay-per-view garnered 121,000 buys, down from 137,000 buys the previous year's event, Bragging Rights, received.
Bloody Wednesday (Polish: "Krwawa środa" ) refers to the events of 15 August 1906 in the (Congress) Kingdom of Poland, where the Combat Organization of the Polish Socialist Party (OB PPS) carried out a series of attacks on Russians, primarily police officers and informants.
 This took place in the context of the Revolution in the Kingdom of Poland (1905–1907), and represented one of the biggest actions in the history of OB PPS.
Bloody Wednesday is a thriller movie based on the events of the San Ysidro McDonald's massacre and was directed by Mark G. Gilhuis.
The 1920 Nebi Musa riots or 1920 Jerusalem riots took place in British-controlled part of Occupied Enemy Territory Administration (which would shortly become Mandatory Palestine) between Sunday, 4 and Wednesday, 7 April 1920 in and around the Old City of Jerusalem.
 Five Jews and four Arabs were killed, and several hundred were injured.
 The riots coincided with and are named after the Nebi Musa festival, which took place every year on Easter Sunday, and followed rising tensions in Arab-Jewish relations.
 The events came shortly after the Battle of Tel Hai and the increasing pressure on Arab nationalists in Syria in the course of the Franco-Syrian War.
Night of Champions (2013) was a professional wrestling pay-per-view (PPV) event produced by WWE.
 It took place on September 15, 2013 at the Joe Louis Arena in Detroit, Michigan.
 It was the seventh annual Night of Champions event, and the eighth pay-per-view in the 2013 lineup.
 This event marked the last WWE pay-per-view event took place at the Joe Louis Arena before its closure in 2017.
 The theme of this PPV was that every championship in WWE was defended.
 The event received 175,000 buys, down from the last year's event of 189,000.
The San Ysidro McDonald's massacre was a mass shooting that occurred in and around a McDonald's restaurant in the San Diego neighborhood of San Ysidro on July 18, 1984.
 The perpetrator, 41-year-old James Huberty, shot and killed 21 people and injured 19 others before being fatally shot by a SWAT team sniper.
The Battle of the Viaduct was an event that took place in Chicago due to a much larger and more prolific event, the Great Railroad Strike of 1877.
 The strike began on July 14, 1877 in Virginia, during a time of great economic woe throughout the country, thus it quickly gained momentum, eventually becoming the first national strike in United States' History.
 The city of Chicago was quickly affected by the strike.
 Being one of the most heavily populated cities in America at the time, crowds gathered in extreme numbers to partake in the upheaval.
 One specific area, the Halsted Street viaduct, saw a huge number of people gather and protest.
 They began to get violent, and in return they were met by fierce retaliation from the authorities.
 The conflict that ensued between the two sides quickly turned bloody, and the event that took place became known as the Battle of the Viaduct.