Oct.11 (GMM) Maria de Villota, who lost an eye after a near-fatal Formula One testing crash last year, died early on Friday.
The 33-year-old Spaniard was found dead in a hotel room in Seville, where she was to give a lecture, Cadena Ser radio reported.
Marca sports newspaper said de Villota's family, led by former F1 driver Emilio de Villota, confirmed the death but did not yet know the cause.
"Dear friends, Maria is gone," the Spanish-language statement read.
"I can only pray for her and all her family," Alonso is quoted by El Pais newspaper.
De Villota sustained serious head and facial injuries in July last year when the Marussia she was testing at Duxford, UK, inexplicably drove into the loading ramp of a truck.