New York City Transit President Andy Byford says a large firecracker went off in an F train this morning.

The incident happened around 9:30 a.m. on a northbound train. Byford says the firecracker went off in the rear car of the train while it was at 14 Street.

Approximately 70 people on the train rushed to get off when it happened.

Byford says it’s not clear yet if the person responsible was on the train or if they threw the lit firecracker onto it.

Police met the train at 23 Street and are still investigating.

“We’re going to nail them because that is stupid, reckless, mindless, moronic behavior,” says Byford. “It has no place on the New York subway system.”

Authorities say the person responsible will most likely be charged with felony reckless endangerment.

"You're an idiot, and you're going to be brought to justice," said Byford.

There has been no word yet on any injuries.