SEVILLE, Spain -- The heat, the hard track and the daily grind took their toll on Marion Jones.
The world's top female track and field athlete came to the World Championships seeking a record four gold medals.She leaves with one gold, one bronze and a bad back.
Jones was carried off the track on a gurney Wednesday night after crumbling onto the track in agony during the semifinals of the 200 meters.
An official statement from USA Track and Field said Jones suffered spasms and cramping in her lower back. Further treatment and tests were needed to determine the full extent of her condition.
It's virtually certain that Jones won't be competing any more at these championships, and the rest of her season could be in jeopardy, too.
Australian sprinter Nova Pedris-Kneebone said Jones' absence, no matter how long, would have a severe impact on the sport. "It's tragic," she said. "In my eyes, she's the Wonder Woman of track and field. She's gained so much respect."
Primo Nebiolo, president of the International Amateur Athletic Federation, also was shaken by Jones' injury.
"I was deeply affected by the injury sustained by Marion Jones, and I am sure that millions of fans around the world share this sentiment," Nebiolo said. Jones' injury overshadowed Wednesday's competition, highlighted by six finals.
World record-holder Colin Jackson became Britain's first world or Olympic champion since 1993, winning the 110-meter hurdles with his season's best, 13.04 seconds.
Jackson, the 1993 outdoor champion, completed a sweep of this year's indoor and outdoor titles by outleaning Cuba's Anier Garcia, the runnerup at 13.07.
Jackson said he wished he could have shared his victory with young Scottish hurdler Ross Baillie, who died suddenly on June 19 from a nut allergy.
The Czech Republic's Tomas Dvorak repeated as world champion in the decathlon, amassing 8,744 points -- 250 fewer than his world record -- in the tough, 10-event competition over two sun-baked days.
Dvorak, who blamed the heat for his relatively subpar performance, beat silver medalist Dean Macey of Britain by 188 points.
Charles-Michael Friedek of Germany, who didn't decide to compete until Tuesday because of a heel injury, pulled a major upset in the men's triple jump, beating world record-holder Jonathan Edwards with the year's best leap, 57 feet, 8 1/2 inches.
Edwards finished third at 57-4 1/4 and called his performance "a disaster."
The other winners were Cuba's Daimi Pernia, who took the women's 400 hurdles with a world-leading 52.99 despite nearly falling after smashing the final hurdle; Germany's Astrid Kumbernuss, the 1996 Olympic champion in the women's shot put, won her third world title with her season's best, 65-11/2; and Russia's German Skurygin in the men's 50-kilometer walk at 3:44:23.