Five years ago, Michael Brown, an unarmed black teenager, was shot and killed by a police officer in Ferguson, Mo. The protests and demonstrations that followed included tear gas, riot gear, police officers in armored vehicles, fires and looting.

To some who saw what was happening, it looked as though a small town just outside of St. Louis had been turned into a war zone.

“It was dangerous,” said Eric Thayer, a photographer who arrived in Ferguson a few days after the shooting.

Mr. Thayer was among the four photographers sent to Ferguson by The New York Times to cover the unrest. Reflecting back on what they saw and what it was like to be on the ground in Ferguson five years ago, some say the experience was life changing.