Newsday reports that that the accident happened early Saturday at the LIRR station in Deer Park.
Police say 45-year-old George Seeley of Amityville lost control of his car and crashed into the eastbound platform.
Seeley was taken to Southside Hospital in Bay Shore, where he died of his injuries.
Train service on the Ronkonkoma Branch was suspended for a short time.
LIRR crews are making temporary repairs to the damaged platform.
