Chelsea and State Police are investigating a one-vehicle crash around 1 a.m. on Cherry Street that sent both occupants to Mass. General - where one survived and the other didn't.
Police say the driver of the 2001 GMC SUV, 35, died. His passenger, 47 and also from East Boston, remains hospitalized.
Police say the vehicle was operating at a high rate of speed when it plowed through a signpost and then slammed into a building.