>> TANIA AND CHRISTINE THAT PRESS CONFERENCE JUST WRAPPED UP MINUTES AGO. WE ARE LEARNING THAT THE FOUR PEOPLE SHOT AND KILLED WERE PASSENGERS ON THE TRAIN AND IT HAPPENED WHILE THE TRAIN WAS MOVING. IT WAS SHORTLY BEFORE 530 THIS MORNING. FOREST PARK POLICE SAY THEY RECEIVED A 911 CALL AT FIRST FOR THREE PEOPLE SHOT ON THE TRAIN AT THIS BLUE LINE STATION. ONCE HERE, THOUGH, THEY CLEARED THE TRAIN STATION AND INSTEAD FOUND FOUR SHOOTING VICTIMS, THREE OF WHOM WERE DEAD ON THE SCENE. THE FOURTH LATER DIED AT LOYOLA UNIVERSITY MEDICAL CENTER IN MAYWOOD. THE SHOOTING HAPPENED ON TWO DIFFERENT TRAIN CARS. POLICE SAY. AS FOR THE SUSPECT, THEY RAN AWAY FOLLOWING THE SHOOTING, BUT FOREST PARK POLICE, WITH THE HELP FROM CTA SECURITY, WERE ABLE TO FIND THEM THROUGH SURVEILLANCE VIDEO. THE PERSON MATCHING THE DESCRIPTION WAS FOUND ON A PINK LINE TRAIN WITH A GUN, AND WAS TAKEN INTO CUSTODY. THE FOREST PARK MAYOR SAYS. POLICE RESPONSES TO THIS SPECIFIC CTA STATION HAVE INCREASED RECENTLY FOR THINGS LIKE OVERDOSES AND CRIMINAL ACTIVITY. THE MAYOR AND POLICE CHIEF JUST SPOKE. TAKE A LISTEN. I MEAN, IT'S A HORRIBLE SITUATION. >> YOU KNOW, IT'S DEFINITELY SOMETHING THAT YOU DON'T WANT TO WAKE UP TO. YOU KNOW, IT'S A MONDAY MORNING ON A HOLIDAY. EVERYONE'S SUPPOSED TO BE, YOU KNOW, ENJOYING THEIR TIME OFF TIME WITH THEIR FAMILIES. IT'S LABOR DAY, YOU KNOW, SO TO ACTUALLY HAVE TO BE HERE, YOU KNOW, TO ADDRESS A SITUATION LIKE THIS, IT'S YOU KNOW, HORRIBLE. >> AND AT THIS HOUR, THE CTA SAYS FOREST PARK BOUND BLUE LINE TRAINS ARE RUNNING AT THIS HOUR. BUT WITH RESIDUAL DELAYS. AS FOR