Father of three boys, track worker Louis Gray, was killed by a G train during maintenance Thursday morning. View Full Caption HANDOUT

BROOKLYN — A worker was killed and another injured when a G train pinned them against the subway wall as they were preparing some track work early Thursday morning, officials said.

A trio of workers were setting up a safe work zone on the southbound track of the G line between the Fort Hamilton and Church Street stations minutes after midnight when a train came around a curve and pinned two of them, killing 53-year-old Louis Gray, according to MTA, NYPD and transit union officials.

Gray, who lived in Brooklyn and worked with the MTA since 2001, was pronounced dead at Maimonides Hospital, police said.

Jeffrey Fleming, 49, was treated for torso injuries at Methodist Hospital, where he's listed in stable condition, police said.

It doesn't appear that the third worker was injured, the MTA said.

Gray's wife, Mary Abdul-Laatif, 57, described him as a family man with three boys who loved helping people commute across the city.

"I’m kind of numb right now, I’m still in shock," Abdul-Laatif told DNAinfo. "I would like a full investigation into this."

Abdul-Laatif added that Gray, who started as a conductor before becoming a track worker, had expressed concerns before about his safety on the job.

Both the MTA and NYPD are investigating the incident.

"We extend our deep-felt condolences today. The safety of all our workers is paramount and we are in the process of investigating this tragic incident," New York City Transit Authority President Robbie Hakim said.

The authority has stopped all non-emergency track work in the immediate aftermath of the incident, officials said.

G train service was disrupted immediately afterward, but resumed regular operation by 1:20 a.m., officials said.

John Samuelsen, president of the Transit Workers Union Local 100, questioned the MTA's ability to safeguard workers.

"This tragedy highlights the extreme danger transit workers are in every time they step on the tracks," he said.

At least 235 transit employees have been killed on the job since 1946, many of them struck by trains while performing maintenance or construction work, according to TWU statistics.

"Here we have two transit workers run down by a train while performing routine maintenance. The NYC Transit Authority can't protect us so they damn well better pay us."