Video of Ahmed el Ahmed disarming one of the gunmen has gone viral, and officials around the world have hailed his bravery.

Lightspeed Venture Partners, a Silicon Valley venture firm, has amassed more than $9 billion to invest in artificial intelligence. That is its biggest haul.

Two men toting long guns opened fire on hundreds of people who were celebrating Hanukkah on Bondi Beach in Sydney, the core of the Australian city’s Jewish community.

After his son was repeatedly attacked, Rick Kuehner reached out to his suburban school, to the police and to other parents. The violence only got worse.

To mark the winter holidays — an especially popular time to break up — we asked people around the world for their most striking parting words to each other.

Medetomidine, a veterinary sedative, mixed into fentanyl has sent thousands to hospitals, not only for overdose but for life-threatening withdrawal. It is spreading to other cities.

José Antonio Kast, who was elected president on Sunday, is the latest conservative to rise to power promising strict law and order measures.

The columnist believes America’s real political contest is in the center.

We are headed for more confrontation, more brinkmanship, more war.

The Air Force refueling tanker was flying without its location transponder activated and could not be detected by air traffic control.