The state Department of Motor Vehicles office in Massapequa was evacuated Thursday after a malfunctioning heating system caused a gas leak, authorities said.
Nassau police and fire officials said the building was evacuated after a 911 call was received about 12:15 p.m. reporting "the smell of gas."
National Grid spokeswoman Wendy E. Ladd said local fire department officials turned off two rooftop heating units by the time utility workers arrived.
"The units were turned off, and there was no more smell of gas," Ladd said.
Tests inside and outside the building showed the building was safe, she said.
She said state DMV officials will have to check and repair the units before National Grid will turn the gas back on.
Police said people were allowed to return to the DMV office at 1 p.m.