The fire sucks. I know that racing cars undergo a stringent process to mitigate chance of fire during their transport. Things like battery maintenance (more stable charged to some minimum), insuring each battery is thermally stable and cool enough to transport, damage inspection prior to shipment, no swelling, Even then, each car is shipped enclosed in a crate designed to mitigate the spread of fire. Couldn’t tell if the bikes were shipped in those crates. Regardless, Li-ion batteries are not easy to put out. Even RC car batteries require proper maintenance to avoid issues.