Two gunmen opened fire on a Hanukkah gathering on December 14 in Sydney, Australia. The celebration was held on Bondi Beach, a popular tourist destination, and was attended by about 1,000 of Sydney’s Jewish population.

15 people were killed in the attack, including a 10-year-old girl, and at least three dozen more were injured. Among the victims is Rabbi Eli Schlanger, who is mourned by an extensive Jewish and non-Jewish Australian community. The full list of victims has not yet been released.

The gunmen—a 50-year-old man and his 24-year-old son— were carrying long-barelled guns. The father immigrated to Australia on a student visa in 1998 and held a recreational gun license; the son is an Australian-born citizen and came to the attention of authorities in 2019 “on the basis of being associated with others,” said Tony Burke, Australian Home Affairs Minister.

The older shooter was shot by police at the scene, and the younger is being treated for critical injuries. He will likely face severe criminal charges, including at least 15 counts of murder.

This attack is being regarded as terrorist action, and represents another in a recent uptick of antisemetic attacks in Australia and worldwide.

That said, Australia has a fairly low incidence of mass shootings, due in part to the strict gun laws imposed after a massacre in 1996 that killed 35 people. Australian leaders have promised to crack down even harder on gun access after this tragedy.

Ahmed Al Ahmed, a bystander at the time of the attack, is being regaled as a hero after sneaking up on and disarming one of the gunmen. His actions likely saved countless lives.

Australia is in mourning after a senseless attack on what was supposed to be a day of joy and celebration.