On this date, January 7, 2015, Two gunmen commit a mass shooting at the offices of Charlie Hebdo in Paris, killing twelve people and injuring another eleven. This event was known as the Charlie Hebdo Shooting, I will post the information from Wikipedia.
INTERNET SOURCE: https://en.wikipedia.org/wiki/Charlie_Hebdo_shooting
On 7 January 2015 at about 11:30 local time, two brothers, Saïd and Chérif Kouachi, forced their way into the offices of the French satirical weekly newspaper Charlie Hebdo in Paris. Armed with assault rifles and other weapons, they killed 11 people and injured 11 others in the building. After leaving, they killed a French National Police officer outside the building. The gunmen identified themselves as belonging to the Islamist terrorist group Al-Qaeda's branch in Yemen, who took responsibility for the attack. Several related attacks followed in the Île-de-France region, where a further five were killed and 11 wounded.
France raised its Vigipirate terror alert and deployed soldiers in Île-de-France and Picardy. A massive manhunt led to the discovery of the suspects, who exchanged fire with police. The brothers took hostages at a signage company in Dammartin-en-Goële on 9 January and were shot dead when they emerged from the building firing.
On 11 January, about two million people, including more than 40 world leaders, met in Paris for a rally of national unity, and 3.7 million people joined demonstrations across France. The phrase Je suis Charlie has become a common slogan of support at the rallies and in social media. The staff of Charlie Hebdo continued with the publication, and the following issue print ran 7.95 million copies in six languages, in contrast to its typical print run of 60,000 in only French.