A 42-year-old Port Huron man died in a crash early yesterday in Isabella County.  Reports say Jeffery Allen Brennan was driving on East Deerfield Road in Union Township when apparently lost control of his pickup and went off the roadway sometime between 2 and 7 a.m.  According to a statement from the Isabella County Sheriff Department, Brennan and a  27-year-old passenger, Nathan Duane Myers of Casco Township, were both ejected from the vehicle.  Authorities say Brennan was pronounced dead at the scene when rescue crews responded at approximately 7 a.m. yesterday.  Myers was taken to McLaren Central Michigan in Mount Pleasant before being airlifted to Hurley Medical Center in Flint.  Neither man was wearing a seatbelt and the incident remains under investigation.