A UPS truck is allowed to return to the facility after the shooting. // Andy Bosselman

The survivor of a mass shooting, his life changed today. And tonight, he’s all alone.

At about 8:45 this morning, “Mr. O,” a UPS worker who sorts packages, was finishing a shift that started at 3 am. Then a mass shooting broke out.

Around 2:45 this afternoon, we found him across the street, leaning against a wall, staring silently at the four story building at the center of the shooting.

“I saw three coworkers die today in front of me.”

His eyes filled with tears as he described watching what he knew was a futile attempt at C.P.R. on one of his coworkers.

Unsure where to go, he wanted to see his kids. But they are in another city, with his wife, whom he divorced recently. He moved to San Francisco in March, where he has no family. No close friends.

His life changed today. And tonight, he’s all alone.

This is the first ‘breaking news’ story I’ve covered.

KALW News (audio): UPS employee shares insights about San Francisco mass shooting

KALW News (audio): Morning shooting leaves four dead at UPS facility in San Francisco