Twenty years ago tanks rolled into Beijing’s Tiananmen Square to crush the biggest pro-democracy movement in history. Hundreds were killed, thousands jailed and many fled to escape persecution. Here exiled leaders of the student revolution tell their remarkable stories and reveal how, after being forced to build new lives, they remain haunted by its bloody legacy

The World Health Organization warned on Wednesday that a global flu pandemic was imminent, raising its threat level as the swine flu virus spread and killed the first person outside of Mexico, a toddler in Texas.

“Influenza pandemics must be taken seriously precisely because of their capacity to spread rapidly to every country in the world,” WHO Director General Margaret Chan told a news conference in Geneva.

“The biggest question is this: how severe will the pandemic be, especially now at the start,” Chan said, but added the world “is better prepared for an influenza pandemic than at any time in history.”

Fears of a global swine flu pandemic grew with new infections in the United States and Canada on Sunday, and millions of Mexicans hid indoors to avoid a virus that has already killed up to 81 people.

While the only deaths have been in Mexico, the flu is spreading with 20 cases in the United States and six in Canada, and possible cases as far afield as Europe and New Zealand.

A video tape smuggled out of the United Arab Emirates shows a member of the country’s royal family mercilessly torturing a man with whips, electric cattle prods and wooden planks with protruding nails.

A man in a UAE police uniform is seen on the tape tying the victim’s arms and legs, and later holding him down as the Sheikh pours salt on the man’s wounds and then drives over him with his Mercedes SUV.

The Colorado River is a critical source of water for seven Western states, each of which gets an annual allotment according to a system that has sparked conflict and controversy for decades. But in an era of climate change, even greater difficulties loom.

The scope of those potential problems is detailed in a study being published in The Proceedings of the National Academy of Sciences. Tim P. Barnett and David W. Pierce of the Scripps Institution of Oceanography report that under various forecasts of the effects of warming temperatures on runoff into the Colorado, scheduled future water deliveries to the seven states are not sustainable.