FORT LAUDERDALE, Fla.—Brightline trains killed one person and seriously injured another in separate accidents less than 12 hours apart, the latest in a spate of collisions plaguing the higher-speed passenger trains since the railroad recently resumed operations. Tuesday night’s death was the ninth involving Florida’s privately-owned passenger railroad since it resumed operations in November after an 18-month shutdown caused by the COVID-19 pandemic. It’s the 57th since Brightline began test runs in 2017, giving it the worst per-mile fatality rate in the nation, according to an ongoing Associated Press analysis that began in 2019. Investigators found none of the deaths were the railroad’s fault, determining that many were suicides or drivers or pedestrians trying to beat the trains. The trains travel up to 79 mph through densely populated urban and suburban areas along about 70 miles of track between Miami and West Palm Beach that it shares with the Florida …