SAN FRANCISCO (CBS SF) — One man was dead, another hospitalized with life-threatening wounds and a San Francisco Mission District street filled with yellow evidence markers early Tuesday after a gunman opened fire, authorities said.

San Francisco police said they received calls reporting shoots being fired near the intersection of 16th and Mission streets at around 3 a.m.

Arriving officers discovered two men on the ground suffering from gunshot wounds. Both were transported to San Francisco General Hospital where one of the men died of his wounds, the other was fighting for his life with critical injuries.

Police were not releasing the identity of the victims but described them as African American males aged 46 and 33.

The busy Mission Street corridor remained blocked off while investigators gathered evidence, sought surveillance video and canvassed for possible witnesses.

No suspects were in custody and San Francisco police have not released a description of the gunman.

Anyone with any information on the case is asked to call San Francisco police at (415) 575-4444 or to text TIP411 and to begin the message with “SFPD”.