Marshfield police are looking at speed and alcohol as possible factors in the fiery car crash Feb. 4 that killed 18-year-old Michael Harrington, police Captain Phillip Tavares said. Police cannot say for certain alcohol was a factor, but they are investigating Harrington’s whereabouts before the crash. The vehicle hit a tree near 509 Highland St. at 4:32 a.m. Tavares said there is no evidence Harrington was using a cellphone, and the stretch of road where the crash occurred is not particularly dangerous, though it is poorly lit. Harrington was enrolled at Marshfield High School as of October, but it was not clear whether he was still attending the school, Tavares said. “My heart goes out to the family,” he said.