Multi-event world champions have rough day at Tokyo Olympics

Katarina Johnson-Thompson, of Britain, reacts after falling during a heat in the heptathlon women's 200-meter at the 2020 Summer Olympics, Wednesday, Aug. 4, 2021, in Tokyo. (AP Photo/Martin Meissner)

Niklas Kaul, of Germany, is assisted on the track in a heat of the men's decathlon 400-meter at the 2020 Summer Olympics, Wednesday, Aug. 4, 2021, in Tokyo. (AP Photo/Martin Meissner)

Katarina Johnson-Thompson, of Britain, reacts after dropping to the track during a heat in the heptathlon women's 200-meter at the 2020 Summer Olympics, Wednesday, Aug. 4, 2021, in Tokyo. (AP Photo/Petr David Josek)

Niklas Kaul, of Germany, is taken off the track in a heat of the men's decathlon 400-meter at the 2020 Summer Olympics, Wednesday, Aug. 4, 2021, in Tokyo. (AP Photo/Martin Meissner)

Katarina Johnson-Thompson, of Britain, reacts after dropping to the track during a heat in the heptathlon women's 200-meter at the 2020 Summer Olympics, Wednesday, Aug. 4, 2021, in Tokyo. (AP Photo/Petr David Josek)

Niklas Kaul, of Germany, competes during the men's decathlon high jump at the 2020 Summer Olympics, Wednesday, Aug. 4, 2021, in Tokyo. (AP Photo/Morry Gash)

Katarina Johnson-Thompson, of Britain, reacts during a heat in the heptathlon women's 200-meter at the 2020 Summer Olympics, Wednesday, Aug. 4, 2021, in Tokyo. (AP Photo/Martin Meissner)

Katarina Johnson-Thompson, of Britain, reacts after falling during a heat in the heptathlon women's 200-meter at the 2020 Summer Olympics, Wednesday, Aug. 4, 2021, in Tokyo. (AP Photo/Martin Meissner)