After the postmaster discovered two large and unmarked packages in front of the post office, he called police. Police arrived and closed the street temporarily. They locked down the U.S. Post Office, and had it evacuated at around 11:00 in the morning while they investigated the packages.
The bomb squad was deployed, and an x-ray robot was brought to look at the contents of the two boxes. Upon examination it was determined that both packages contained car seats.
At this time, it is not known why the two packages were abandoned outside the post office, but this is being investigated by police.
The post office was deemed safe at around 12:00 and workers were allowed back in the building.