Are you thinking of Jane Mansfield?
She didn't die on the beach, but she did die in Biloxi, Mississippi, or just outside of it.
Her lawyer & companion, her driver, and her 3 children were heading to New Orleans with her in 1967 when they rear-ended a tractor trailer at a high rate of speed. The 3 adults in the front seat were all killed instantly, while the 3 children in the back seat, asleep, all survived with minor injuries.
