The passenger in the one-car crash on June 19 died Sunday.
Shelton Johnson, 22, was in critical condition until Sunday night when he died in the hospital, police said.
According to police, 26-year-old Aqwan Huff was killed when the Nissan Maxima he was driving struck a pole at the corner of East Center St. and Holl St at 8:30 Thursday night. He was pronounced dead on scene.
Johnson was transported to Hartford Hospital and later flown by Life Star to Bridgeport Burn Center.
Police said it appears that speed or driver impairment may have been factors in the crash.
Manchester police's traffic unit and the Metro Traffic Reconstruction Team continue to investigate the crash.
Anyone with information or who may have witnessed the accident is encouraged to call Ofc. Jason Moss at 860-645-5560.