Triumph, tears and violent death in Beijing's five-ring circus

After seven years of expectation, China's Olympics are under way – but sport is far from being the only story

The Olympic Games began in earnest yesterday with the first gold medal, the first victim of Beijing's climate, the first casualty of the intense pressure the Chinese press is applying to home athletes, and the first violent death.

After the choreography and euphoria of the opening ceremony, reality kicked in hard, not least for the British squad who saw their first real medal hope, Craig Fallon in the judo, fail to win even a bronze. But there was reality of a far uglier order when the father-in-law of an American volleyball coach was murdered as he saw some of the Chinese capital's sights. He, his wife, and their tour guide were attacked by a 47-year-old man, who then jumped to his own death from high up the Drum Tower, a 700-year-old 45m-high monument just three miles from the main stadium.

Attacks on foreigners in Beijing are rare, and this incident was proof that even the 100,000-strong security force deployed by the Olympics' organisers cannot be everywhere.

What may yet prove to be a more sustained theme of these Games is the local climate and air quality. In the first event to test athletes' ability to withstand the heat and smog of a Beijing summer – the men's 245km cycling road race from the Forbidden City in Beijing to the Great Wall – more than a third of the riders dropped out, citing pollution and heat.

One of the favourites, Stefan Schumacher of Germany, said the humidity and smog made a hard course even tougher. "I have a very, very strong headache," he said after abandoning the race. "I suppose it's the pollution. It feels like you're at 3,000 metres because of the air. You cannot breathe. The air is thick and there is smog." The 2007 Tour de France winner, Alberto Contador, could not handle the heat either. "I just didn't have any more strength in the legs," he said after giving up. The race was won by Spain's Samuel Sanchez.

Tennis officials now say they may allow heat breaks during matches to help players cope with stifling humidity and heat in the high 90s Fahrenheit (above 35C). Competitors have said that the conditions are among the toughest say they have ever faced.

It was heat of a different kind that did for China's anticipated first gold medal. In the women's 10m air-rifle, Katerina Emmons of the Czech Republic won after the pre-Games favourite, Du Li of China, finished fifth and left in tears. "There was pressure for all of us but for her it was even harder," Emmons said of her rival. "I'm sorry, but the Chinese press is putting a lot of pressure on Chinese athletes."

"I wasn't fully prepared for the pressure of competing at home," said Du, who won gold in Athens in 2004. Consolation for the host nation came with golds in women's weightlifting and men's shooting.

Elsewhere, the American swimmer Michael Phelps began his quest for a record eight gold medals by winning his heat in the 400m individual medley in an Olympic record time; in sailing Britain's Ben Ainslie recovered from 11th in his first Finn class race to win the second, and now lies third; and world champions Sarah Ayton, Sarah Webb and Pippa Wilson lead the field in the Yngling class.

The other sporting headline was less encouraging: positive doping tests on a Greek sprinter and a Russian steeplechaser.

Yet, according to one British security expert, the biggest threat to the Games remains Islamic militants from Xinjiang province, home to eight million Muslim Uighurs, who want autonomy. They have been linked to several recent attacks, and last week issued a video of a bomb factory and urged people to "stay away from the Games".

The Uighur independence movement has become radicalised by Islamists in neighbouring countries. Many Uighur separatists are training in Pakistan and Afghanistan – several operatives linked to a plot to blow up a China Southern flight this year were carrying Pakistani passports. If there is a significant attack in Beijing, as yesterday's murder by a lone knifeman shows, it is more likely to be away from the Olympic venues, perhaps on the hard-to-protect public transport systems.

Britain's medal hopes this week

Today:

Rowing: Britain's top rower, Katherine Grainger, competes in the quadruple sculls heats, and Olympic bronze medallist Sarah Winckless competes in the rowing eights race.

Tennis: British star Andy Murray plays in the men's doubles with his brother, Jamie.

Women's Gymnastics: Features Beth Tweddle.

Tomorrow:

Diving: Teenage diver Tom Daley, 14 – the youngest athlete in the Games – and his partner, Blake Aldridge, dive in the 10m synchronised event.

Badminton: Anthony Clark and Donna Kellogg compete in the badminton mixed doubles.

Tuesday:

Archery: Features Alison Williamson.

Wednesday:

Men's hockey: GB v the Netherlands.

Thursday:

Swimming: Mark Foster swims in the men's 50m freestyle, in his fifth Olympic Games.

Friday:

Athletics: Jo Pavey runs in the 10,000m. Kelly Sotherton goes for the heptathlon title, and Philippa Roles competes in the women's discus.

Men's hockey: GB v South Africa

Saturday:

Cycling events: featuring Bradley Wiggins, Chris Newton and Rebecca Romero.

Athletics: Christine Ohuruogu runs in the women's 400m heats. Kelly Sotherton continues her quest for heptathlon gold.