The Baldwin Public Library closed Tuesday morning after 12 people fell ill, Nassau County police said.
The incident occurred at 11:06 a.m., a Nassau police spokeswoman said. She said five people refused medical attention and seven were transported to Nassau University Medical Center in East Meadow.
"We are conducting some tests, but basically the library's closed until maintenance crews inspect the onsite equipment and ventilation," the spokeswoman said.
On its website, the library has posted this notice: “The Baldwin Public Library is temporarily CLOSED as of 12 noon, Tuesday, Jan 4th. Please call to find out when we will be reopening."