A leaking hazmat package is discovered by a warehouse worker four days after a shipment arrived, even though the leak likely began during transport earlier. From what point does the 30-day clock for filing DOT Form F 5800.1 begin to run?

49 CFR 171.16 (Detailed hazardous materials incident reports — discovery-based deadline)

'Discovery,' not the original event, starts the clock, so a carrier can still be within its legal deadline even if a problem surfaces several days after a shipment arrives, as long as the report is filed within 30 days of actually finding out about it.