Some U.S. shipyards fear roughly 8,000 shipping containers that passed through Vietnam are explosive, according to Seattle's KING-5 TV outlet via MSNBC.
After hearing reports of dock workers killed by exploding containers abroad -- two in Vietnam and one in Brazil -- some U.S. longshoremen are refusing to handle select containers, reported San Francisco's KGO-TV.
All of the suspect shipping containers are "reefers" -- shipyard slang for refrigerated containers -- and bad coolant is among the suspected culprits.
Still, no one's quite sure what's caused the reefers to explode and if it'll happen again. At least one shipping line, APL, has distanced itself from the mystery by halting repair work in Vietnam.
The biggest fear, one labor union representative told KING-5, is a container on a truck bed "exploding next to a mom and her kids" on a highway.