Police are trying to figure out what prompted a partially naked man to jump into a downtown Toronto fountain head first early Sunday morning.

The man was pronounced dead after emergency crews found him floating in the water with no vital signs.

Witnesses told police the man, who is believed to be in his 30s, dove head-first into a fountain at Berczy Park at around midnight. The park is located in the Front and Wellington Streets area.

Toronto police say they are treating the case as a "death by misadventure."