MARCELLUS, N.Y. -- What U.S. Postal officials initially said was a small mercury spill due to broken light bulbs at a village post office actually is a bigger deal than that.

The spill involves a package of as much as 8 pounds of bulk mercury, according to a Facebook post from an employee at the post office, and at least some of it apparently leaked.

The spill of mercury caused the closure of the Marcellus post office last Monday. It could reopen by the end of this week.

It now has emerged that a postal facility in Rochester that the hazardous metal was routed through was shut down too, a spokeswoman confirmed. Both facilities remain closed as of Wednesday.

Mercury from the leaky package also reached Driver Middle School in Marcellus, according to the schools superintendent.

“The Marcellus Central School District was notified by the U.S. Postal Service late last week that it had been sent packages possibly contaminated by the mercury leak...” the district wrote in a letter sent to parents this week. “Testing ... confirmed the presence of mercury residue in the carpeting of the Driver Middle School staff mailroom and the adjacent room that contains the district office safe.”

As a result, the area has been cordoned off until the carpet can be cleaned or removed, the district wrote.

There is no danger to students or staff from the residue, school officials said.

A video published on YouTube by a Marcellus resident shows a large scene with bustling cleanup activity around 2 a.m. Monday, Sept. 2, about a week after the spill.

In the video, specialists in white jumpsuits make their way in and out of a large mail truck. Another, smaller mail truck is covered by a tent.

Maureen Marion, a spokeswoman for the postal service, said Wednesday she was initially given incorrect information about the nature of the spill when she said last week that broken light bulbs and switches were the cause.

Asked to confirm that the shipment involved 8 pounds of mercury, Marion said she didn’t know how much mercury was in the shipment.

“About all I know that I can share is that it was a single package,” she said.

She declined to say where the package came from and where it was headed, citing an ongoing investigation. She also declined to say whether a criminal investigation was ongoing.

Investigators are working on figuring out which vehicles, facilities and routes the contaminated package might have taken, she said.

As for why crews opted to work on the vehicles and the Marcellus office at 2 a.m., Marion said investigators are working around the clock to ensure the office opens up as quickly as possible.

No one has been harmed by the mercury, she said, and Marcellus residents can pick up their mail in Camillus.

Mail that was in the post office during the time of the exposure was tested, cleared and delivered on Friday, according to the postal service.

Employees could be seen barefoot outside the post office as investigators figured out what to do next. Employees were told to take their shoes off in case they were contaminated.

Mercury is liquid at room temperature.

The U.S. Centers for Disease Control reports that human health effects from exposure to low levels of elemental mercury -- the type commonly found in light bulbs -- are unknown. Very high mercury concentrations can cause severe lung damage.