Many New Jersey residents opted to do most of their holiday shopping online this year but are worried that those package won’t arrive in time.

Those worries are not without reason due to the amount of volume the distribution centers must handle. A fire Monday involving 10 UPS trucks and a loading facility in Maryland is also slowing down some deliveries.

UPS handles deliveries for online giant Amazon. The company recently said that it was adding up to two days for some deliveries.

But the United States Postal Service may be able to step in to get gifts to consumers on time.

“We do Sunday deliveries throughout the year in our busier communities for Amazon packages,” says USPS spokesman George Flood.

Flood says that he expects the Postal Service to deliver 850 million packages in time for the holiday, 10 percent more than last year. The service has also hired seasonal workers to help get the job done.

There will be 16 post offices throughout the state that will have retails window hours on Dec. 3, 10 and 17 for people who may need to ship out packages.

The cutoff date for priority mail delivery is Dec. 22. Flood says that it is best not to wait.