Nick Hogan's Crash Victim Brother Dies After Car Accident

More tragic news for the family of John Graziano -- Nick Hogan's infamous 2007 crash victim -- TMZ has learned John's younger brother Michael has died from injuries he sustained in a car accident earlier this month.

As we previously reported, Michael was a passenger in a 1994 Volvo which slammed into the back of a dump truck on a Florida highway on April 3. Like his brother John, he was not wearing a seat belt.

Michael was rushed to the hospital where he remained in critical condition for several days.

Now, officials say Michael has "expired from his injuries sustained in the April 3rd traffic crash."

The cause of the crash is under investigation.

Unlike Nick Hogan -- who spent some serious time in jail for the 2007 crash -- no charges have been filed against the driver in Michael's accident ... yet.