GUILDERLAND — Maintenance workers at the Woodlake Apartments said that on Wednesday morning they heard a loud explosion and then what sounded like a rush of liquid, similar to a waterfall.

The noise they described was actually a sudden release of pressure from a gas pipe that was hit by construction workers on the state Thruway, according to Sean Maguire, spokesperson for the Guilderland fire districts. The Thruway runs next to the Guilderland apartment complex.

The shovel of a backhoe appeared to have hit a buried gas line.

“Our first priority was to make sure the construction crew was unharmed, and our next priority was to stop traffic in the area and evacuate residents living downwind of the incident,” Maguire told The Enterprise yesterday.

One of the main concerns with the damage to the gas line was the potential for it to ignite, which is why local fire departments responded, including McKownville, Westmere, and the City of Albany.

People living in homes along a portion of Schoolhouse Road, including in the Woodlake Apartment complex, were evacuated. Schoolhouse Road has an overpass above the portion of the Thruway where the pipe was damaged, and Woodlake Apartments is adjacent to the Thruway.

“We wanted to make sure the gas wasn’t traveling with the wind and getting into people’s homes,” said Maguire. If natural gas is trapped in a confined space, it can replace oxygen and present a health problem, he said.

The evacuation order was lifted after 90 minutes, at about 1 p.m., once National Grid had shut off the gas to the damaged line, and an air quality test had been performed.

“It did scare some people; there was a loud noise and some dust and debris was kicked up, but it was under control pretty quickly,” Maguire said. He said gas will not be restored to the pipe until it has been repaired.