NEW YORK (CBSNewYork) – A workplace dispute turned deadly Thursday in Queens.

Two Amtrak workers got into an argument around 8 a.m. at the Sunnyside railyard near Northern Boulevard.

Police said one employee shot his supervisor in the leg.

The 53-year-old victim was taken to the hospital with non-life-threatening injuries.

Police said the suspect took off in a black SUV and barricaded himself inside the vehicle before shooting himself in the chest.

He was taken into custody and later pronounced dead.

It’s unclear what led up to the argument.

“Amtrak Police are working with NYPD investigating a shooting incident at our Sunnyside Yard location, an equipment and servicing facility in Queens, NY. One employee was transported to a local hospital with non-life-threatening injuries. The suspect is known, and a search for the suspect is ongoing,” Amtrak said in a statement. “The area has been secured by the Amtrak Police Department and NYPD. There is no impact to train operations.”