In the worst of times, the best of humanity asserts itself—a bright light to drive away the darkness that evil brings to the world.

An "amazing, selfless" Christian "angel of a man" proved to be that bright light, at least to one office colleague, on that fateful Wednesday morning in San Bernardino, California, when pure evil visited a group of about 80 people celebrating a holiday party.

They were employees of the San Bernardino County Department of Public Health who had no inkling that death had come to visit 14 of them when two individuals, both fully clad in black including black face masks and armed with pistols and assault rifles, barged into the room and started spraying bullets randomly.

Two employees—Shannon Johnson, 45, and Denise Peraza, 27—who were seated next to each other, suddenly found themselves huddled under the table, with only a fallen chair as shield, as bullets rained down on them, the Los Angeles Times reported.

Johnson wrapped his left arm around Peraza, held her close and told her: "I got you."

A bullet pierced Peraza's lower back, but she survived, thanks to her "friend and hero" Johnson who used his body to shield her. Bullets struck Johnson, killing him.

Peraza, now recovering from her wound, has written a statement describing the horror she experienced during the terrorist attack, which was then emailed to the Los Angeles Times.

Peraza said prior to the mayhem, she and Johnson, an environmental health specialist, were joking about how they "thought the large clock on the wall might be broken because time seemed to be moving so slowly."

Minutes later, she said bursts of deafening gunfire suddenly filled the air, instinctively forcing them and the other people in the room to drop to the floor and take cover under the tables.

"While I cannot recall every single second that played out that morning, I will always remember his left arm wrapped around me, holding me as close as possible next to him behind that chair," Peraza wrote.

She described the terrifying scene earlier to her relatives.

"Everyone dropped to the floor," she said. "The guys opened fire for 30 seconds, randomly, then paused to reload and began firing again."

She said she was shot once in the lower back. When the shooters left the scene, she said everything was silent for about five minutes. Then the police barged into the room and rescued the wounded, including her.

In her statement, Peraza included a picture of Johnson, smiling behind sunglasses and a beard.

She wrote that "amidst all the chaos, I'll always remember him saying these three words, 'I got you.'

"I believe I am still here today because of this amazing man. This amazing, selfless man who always brought a smile to everyone's face in the office with his lively stories about his hometown back in Georgia.

"This is Shannon Johnson, who will be deeply missed by all. This is Shannon Johnson. My friend, my hero," Peraza said.

Her sister Stephanie Rose Baldwin was also full of gratitude to the man who saved her sister's life. She posted on Facebook: "This angel of a man was sitting next to my sister when the shooting happened. He helped protect her from the bullets and we are so grateful for his heroic love."