MBTA Green Line July 31, 2021 7:11 am Investigation Underway After Green Line Collision Officials are investigating a collision between two trollies on the MBTA Green Line B branch that left over 20 people injured on Friday. US & World Videos 5:10 Mental health still suffers stigma in the medical and research fields 2:47 Students face disciplinary action for encampments 2:19 First responders testify in Karen Read murder trial 4:24 Karen Read trial | Takeaways from police, firefighter testimony 3:38 Tech Tuesday: TikTok testing ‘Notes'