World: An indoor pyrotechnic display ran out of control, setting off a fire in a Brazilian nightclub that has killed at least 245 people, many of them university students. A similar fire in Rhode Island in 2003 killed 100. As …

Tech Shock: The death of a young star has rocked the tech world. The Internet genius, activist and sometimes hacker Aaron Swartz hanged himself in his Brooklyn apartment at age 26. Swartz helped invent RSS, a compiler of web feeds, …