A teenager was fatally shot on a train platform in West Philadelphia on Saturday afternoon, according to police.
The Philadelphia Police Department said the shooting took place at a SEPTA station on the 5200 block of Market Street.
The 14-year-old boy was shot in the chest and the arm and was transported by medics to Presbyterian Hospital where he later died, police said.
No arrests have been made and a weapon has not been recovered, police said.
Sources told ABC News Philadelphia station WPVI that an adult man was identified as the suspect and is currently on the run.
According to WPVI sources, the suspect and the teenager had a physical altercation which started when the 14-year-old allegedly hit the suspect.
The suspect then allegedly took out a gun and fired, hitting the victim, and then fled the scene, according to WPVI.
"SEPTA Police are working closely with Philadelphia Police to find the suspect in this case. This is a horrific tragedy, and our thoughts are with the family that has experienced an unimaginable loss," SEPTA said in a statement to ABC News.
The statement added, "SEPTA serves over 600,000 riders a day, and the vast majority get to-and-from their destinations without incident. However, even one violent crime is too many, and we are continuing to adjust police patrols and add officers to our ranks so we can address hot spots while providing police coverage across the system."