Authorities believe Wann was homeless and frequented the intersection.
Witnesses said Wann was walking north in the crosswalk when he exchanged words with two other men walking south, officials said.
One of the men walking south pulled out a knife and stabbed Wann in the chest, according to police.
Authorities said the two southbound men fled northeast from the intersection. They were dressed in dark clothing, witnesses said.
Wann died from his injuries, officials said.
Anyone with information is asked to call Livonia police at 734-466-2470.