Nearly 50,000 members of the International Longshoremen’s Association (ILA) are on strike Tuesday against the nation’s East and Gulf Coast ports, according to the Associated Press, choking off the flow of many of the nation’s imports and exports in what could become America’s most disruptive work stoppage in decades.

Ports along the US east and Gulf coasts have shut down as dock workers went on strike for the first time in nearly five decades. Tens of thousands of dockworkers represented by the International Longshoremen’s Association walked out of major US ports after their employment contract expired at midnight on Tuesday.

Tens of thousands of dockworkers are on strike after the International Longshoremen's Association and the US Maritime Alliance failed to agree.