Federal transportation investigators are looking into an incident that left one MTA worker dead and another injured in Brooklyn. NY1's Jose Martinez filed the following report.

It's as hazardous a job as there is in the subway. Danger is always lurking on the tracks.

For track worker Louis Gray, it arrived early Thursday, when he was fatally struck by a G train in Brooklyn.

A co-worker also was pinned against the tunnel wall. He suffered nine broken ribs, but survived.

"Every time we go down to those tracks, our lives are in danger." said John Samuelsen, president of Transport Workers Union Local 100. "And as you saw this morning, tragedies occur like this far too often."

Authorities say the southbound train struck Gray and coworker Jeffrey Fleming in a curving section of tunnel between the Fort Hamilton Parkway and Church Avenue stations. The men had been setting up lights to alert train operators that workers would be in the tunnel. 

The National Transportation Safety Board opened an investigation to determined what happened. When trains pass, workers are supposed to be in one of the designated spots providing enough space for them to safely stand.

"Any time you're in a curve in the subway, you run the risk of the train operator not seeing you and you not seeing the train. And I'm sure that's what happened today," Samuelsen said.

Gray had worked for the MTA since 2001, Fleming since 1999.

"You had plenty of experience for sure. But experience on the railroad tracks sometimes does not matter," Samuelsen said. "The work environment is so incredibly dangerous that industrial accidents like this are bound to occur."

On Thursday, the union president blasted the MTA in front of track workers in Queens.

"It's documented they can't protect us," Samuelsen said in a video posted to YouTube. "We die on the tracks. We get, we suffer massive casualties on the tracks."

But track worker safety has improved significantly since 2007, when two track workers, Marvin Franklin and Daniel Boggs,were fatally struck by trains in Brooklyn and Manhattan in the span of just five days.

From 1998 to 2007, there were 10 track worker fatalities. Counting Thursday's, there have been three deaths since then.

The MTA says it's expanded safety zones around track workers, forcing trains to go slower for longer distances, a change which has slowed service.

Following this latest death, the MTA said it will review of all safety standards and that all non-emergency track work will be suspended until the investigation is completed.