Update, 9:15 p.m.: The Arborway is clear and open again to traffic, State Police report.
Massachusetts State Police report four teenagers and two adults were seriously injured in a crash around 2 p.m. State Police say their initial investigation shows that an SUV carrying the teens "rolled over center line, struck a pickup with two adults in the opposite lane." AlertNewEngland reports two child car seats were found ejected from vehicles, but that no young children were in them at the time.
The Arborway was shut between Centre/the Jamaicaway and the Forest Hills rotary.
Boston Police advise: