The situation appears to already be under control and the suspect is in custody:
One person was killed and three others were injured Thursday after a shooting on board a public train in Atlanta.
Metropolitan Atlanta Rapid Transit Authority (MARTA) police said the suspected gunman boarded a Blue Line train at the H.E. Holmes station west of downtown Atlanta and opened fire at around 4:30 p.m. local time.
Authorities said the suspect was arrested as he left the West Lake station one stop away. Investigators told Fox 5 Atlanta that they have recovered what they believe to be the gun used in the shooting.
MARTA spokesman Erik Burton said one man was fatally shot, and two men and a woman were shot and wounded.
The three victims who were brought to the hospital alive are in stable condition. A fourth person trampled in the panic was also hospitalized.
The motive for the shooting was unknown.