Usage patterns
〈事〉が次々と起こるfor things (events, problems) to happen one after another
Strange incidents happened one after another in that village.
〈物〉が次々と売れるfor products to sell one after another (in quick succession)
The new game is selling one after another.
次々と〈動詞〉to do something one after another, in rapid succession
Customers came into the shop one after another.
〈人〉が次々と辞めるfor people to quit/leave one after another
Employees left the company one after another.