Summer McIntosh, the 18-year-old Canadian swimming star, rolled to victory Sunday in the women’s 400-meter individual medley, setting a world-championship record and winning her fourth individual gold medal of the event.

Canada’s Summer McIntosh capped a dominant world swimming championships with her fourth gold medal on Sunday, winning the women’s 400-metre individual medley in championship-record time.

Ledecky won with a time of 8:05.62, both a world championships record and the fourth fastest time in the history of the 800m free. Pallister wasn't far behind (8:05.98), with McIntosh claiming bronze (8:07.29).