OAKLAND (KRON) — Think of all the sensitive material you get in the mail–bank statements, credit card bills, maybe even your tax refund, or cash from grandma for your birthday.

Stealing mail is a federal offense, as is stealing an entire United States Postal Service mail truck.

On Tuesday night, KRON has learned that someone stole one in Oakland, and all the mail that was in it, about to be delivered, was also gone.

The number of people affected by this crime is still being figured out. The truck was stolen from the streets of Oakland.

And the search is on now for both the suspects and all the victims. The truck was stolen on Saturday afternoon on 36th Avenue in Oakland.

The mail driver, on her normal route, locked up her U.S. Postal Service truck and got out to deliver mail by foot.

When she got back, the truck was gone.

“Whoever it is broke in, and we are still trying to determine exactly out how they broke in,” U.S. Postal Inspector Jeff Fitch said.

Fitch said the truck was found not long after, but the mail that was inside was all missing.

There is no suspect description, he said, or no way to tell how many people had their mail stolen.

Victims will have to see if anything important never got delivered.

“If anybody realizes, in the next week or two, if they get a credit card statement or a bank statement and any unusual activity, contact us immediately,” Fitch said. “That is information that will lead us to the individuals.”

Fitch did not have a cross street or neighborhood to tell KRON where exactly this happened.

The postal service said this is a federal offense punishable by up to five years in prison.

There is a $10,000 reward for any information leading to an arrest.