While the gas fires and explosions earlier this month were a shock to residents of the Merrimack Valley, not everyone was surprised. Activists who’ve been lobbying against the expansion of natural gas infrastructure say this incident is an example of safety concerns they’ve been raising.

Boston University professor Nathan Phillips knocked on the door of a home in Lawrence in the dark. Under his arm, he carried a box with a portable hot plate for cooking food. This is one of 8,600 households in the area that are without natural gas.

Maria Velasquez answered her door, and Phillips showed her the box he brought her, explaining it’s not a regular hot plate. This one was an induction cooktop.

“The thing about induction cooking is it's slightly different than regular cooking,” Phillips said. “It is really fast. But it requires pots that are magnetic.”

Unlike the hot plates the National Guard handed out this weekend, induction cooktops don’t actually get hot. They use electromagnetic energy to directly heat pots. Phillips and a coalition of environmental groups raised money to buy 170 of these cooktops for residents who lost their natural gas.

“Thank you so much. I appreciate it so much,” said Velasquez. “It's been hectic having to pretty much take everybody out. Not even food shopping — it's just takeout meals every single day. I'm like, I can't anymore.”

At BU, Phillips is a forest ecologist, and his research showed him natural gas leaks are killing trees. That’s led him to become something of an expert on leaks, and an ally to environmentalists who are trying to stop those powerful greenhouse gases from escaping pipes.

“By 2050, we have aggressive climate action plans like the City of Boston, for example, going carbon free by 2050,” he said. “To do that we need to transition off of all fossil fuels including gas. So what's the pathway to transition?”

Phillips is hoping induction cooking can be part of that pathway. He’s been working with the Gas Leaks Allies — a partnership of groups that typically focus on the environmental impacts of natural gas and other fossil fuels. At the same time, safety has always been part of the discussion. But now, that’s moved to the forefront.

Zeyneb Magavi is part of two organizations that are in the Gas Leaks Allies: Mothers Out Front and HEET. She said this crisis illustrates the dangers of natural gas. “It's shocking and yet not surprising,” she said. “And it creates a sense of urgency about moving to a safer solution for our society.”

The climate activism group350Mass is collecting signatures on a petition calling on Governor Charlie Baker to issue a moratorium on new gas infrastructure until an investigation is conducted into the system’s vulnerabilities. Craig Altemose of the group said whenever there’s any kind tragedy, there’s always a sense that people should focus only on the victims, without examining the root cause of the crisis.

“And certainly we need to think about the victims and care for the victims and do everything we can to facilitate a speedy recovery as much as possible,” he said. “But at the end of the day I think it is a rejection of our societal responsibility if we don't look at the root causes as to why we are in the situations we are in.”

In the wake of the Merrimack Valley disaster, the responsible gas utility, Columbia Gas, is offering to pick up the tab for customers wishing to switch to alternative fuels — something these environmentalists are celebrating as a huge opportunity.

But Columbia Gas Spokesman Scott Ferson disputes the notion that natural gas is unsafe. “Delivery of natural gas safely happens every day in Massachusetts to hundreds of thousands of households,” Ferson said. “So the delivery of natural gas is safe. And this was an incident that is not widespread. And Columbia is addressing it.”

“I think the industry, the regulators and even groups like ourselves all agree the real goal for these pipelines is zero instances, and we’re nowhere need that yet,” said Carl Weimer, executive director of the nonprofit organization thePipeline Safety Trust.

Weimer said there are between 120 and 140 significant incidents every year on natural gas distribution and transmission pipelines. “And what that means is someone was either killed, hospitalized or did over $50,000 worth of property damage.”

With millions of miles of pipelines in this country, Weimer said, that is actually pretty rare. But he said people have different ways of looking at risk and deciding what’s safe. “You start comparing it to driving in your own car on highways and it’s probably safer than that, but not so much if it’s your house that blows up because the company didn’t deal with things correctly.”

Even though those incidents may be rare, he said, the tragedy in the Merrimack Valley shows when things do go wrong with natural gas, they can go very, very wrong.