MONTGOMERY, Ala.—A crash that killed 10 people—including nine children—on a rain-slicked Alabama interstate happened after a tractor-trailer truck slammed into vehicles that had slowed down because of minor crashes, according to a preliminary report released Tuesday. The National Highway Safety Board’s initial findings on the fiery June 19 crash that involved 12 vehicles present a chronology of events but don’t assign a cause or blame as the agency continues to investigate. Eight of the victims were in a van from a youth home for abused or neglected children. The report said the van was hit by two commercial trucks. A Tennessee man and his baby in another vehicle were killed. The report says a commercial truck hauling an empty trailer used for moving cars came upon a queue of traffic on Interstate 65 that had slowed and stopped because of earlier minor crashes. The commercial truck, operated by Hansen & …