LAWRENCE — Fire Chief Brian Moriarty said Tuesday morning's evacuation of students from Parthum Elementary School, the second evacuation in the last five days, was caused by the same problem as last week's incident — natural gas leaking from a rooftop heating unit at the school.
The Parthum was evacuated because of the odor of natural gas, but students were allowed to return to the building a short time later. They are resuming classes and are expected to have a normal school days, officials said.
Students were evacuated from the school Tuesday morning after someone reported the odor, according to reports. About 9 a.m. they were let back into the school.
Moriarty said the leaky rooftop unit was shut off, but no other work was needed at the school.
Students from the Parthum were evacuated Thursday of last week when a gas leak was discovered inside the building, three weeks after explosions and fires ripped through the city and two other towns.
City officials and Columbia Gas representatives said this and two other school incidents Thursday morning were not connected to the Sept. 13 explosions caused by over-pressurized gas lines.
Public safety officials said they also received calls from two other Lawrence elementary schools for the smell of natural gas last Thursday morning. Ultimately, all three schools were checked and deemed safe to resume classes. Students from the Parthum, who had evacuated to Lawrence High School, returned to their school to finish out their day.
Gas leaks happen often, Fire Chief Brian Moriarty said.
However, when they happen just weeks after a massive natural gas disaster that displaced thousands of people, apprehensions come to the forefront.
Lawrence Mayor Daniel Rivera announced on Twitter the evacuations were not connected to the Sept. 13 incident.
The problem at Parthum appeared to be from a rooftop unit and boiler leaking gas, city officials said.
Columbia Gas — the company responsible for the series of gas explosions Sept. 13 that caused destruction across homes in Lawrence, Andover and North Andover — was also on scene at Parthum.
In a video update posted to Twitter, David Nelson, operations manager for Columbia Gas of Massachusetts, said some of the rooftop units and their hot water heaters had "small leaks that were recycling through the system."
About an hour after the Fire Department received word of a gas odor at the Parthum, calls came in from the Oliver School and the Arlington School for the same problem.
Columbia Gas President Stephen Bryant told reporters there was no risk.
"These three schools are not on that distribution system at all. There's no relation, other than I think there's a heightened sense of observation, people reacting to anything that appears to be the odor of natural gas."
Moriarty said first-responders investigated all three calls. The air was tested at the Oliver Partnership School and no gas was found. The gas odor at Arlington School was caused by a crew purging gas in the building to prepare the boilers for winter.
"It was routine maintenance to get his boiler ready for the school," said Moriarty.
In the video update, Nelson said the call at Oliver School was the result of sewer gas, not natural gas.
"We can assure you all three facilities are safe," he said.
Moriarty said everyone did what they were supposed to do, by calling 911 and leaving the building when they thought they smelled natural gas.
"Leaks happen all the time. ... It's not a situation to be panicked about. We appreciate the seriousness of how everyone's excited about this, but it's not dangerous. Everyone did the things they were supposed to do."
Moriarty said given people's anxieties in the wake of the Sept. 13 incident, gas work in the schools will now be done on nights and weekends.