Officials haven't made a formal announcement on the exact cause with racing abandoned.
Two horses die in electrocution mishap at Newbury
NEWBURY // Two horses have collapsed and died in the parade ring at Newbury Racecourse amid fears they were electrocuted.
The reasons for the deaths of Fenix Two and Marching Song before Saturday's first race were not immediately announced by officials at the southern England course.
But Andy Turnell, trainer of Marching Song, says "it looks like they've been electrocuted."
Marching Song's part owner Graham Thorner added that "three people said they were getting a shock off the horse. My fellow (Marching Song) seemed perfectly all right and I was about to leg him up but he just went straight down."
Racing was abandoned at the course as the investigations continued.
Newbury chairman Christopher Spence says "we can't be certain what it is, we all think it's electric, but we don't know."