Getting fast, comprehensive and accurate information is crucial during emergencies like the devastating wildfires still raging in the Los Angeles area. Over the last two terrifying weeks, one app has become the place to find it: Watch Duty.

Operated by a nonprofit, the app was launched in 2021 to track wildfires in Northern California. It now provides coverage for more than 20 states.

Marketplace’s Meghan McCarty Carino spoke with David Merritt, Watch Duty’s chief technology officer, about how it all came together. The following is an edited transcript of their conversation.

David Merritt: A close friend of mine, John Mills, moved from San Francisco, bought a property in Healdsburg, which is about 90 minutes north. A lot of fires around there in Sonoma County. And I think within the first six months or a year, he had two major fires that came probably within, like, a half-mile and a quarter-mile of his property. And he was really frustrated and, you know, alarmed at the lack of information. He learned about one of those fires because he heard a helicopter, so he found people that were doing reporting, good reporting on some of these fires, on Facebook and Twitter. And he had the idea, why don’t we build a platform for this? Why don’t we give a voice to what these reporters are already doing and make a much better solution? We built it in 80 days, an initial proof of concept, launched it, and it was a huge hit. We launched in four counties — Sonoma, Napa, Lake and Mendocino — all in Northern California that first year, and firefighters loved it, the community loved it. We got a couple 100,000 people that used it, and we realized that there was really something there.

Meghan McCarty Carino: It’s so incredible that firefighters are using this, that you’re providing data that, I mean, even firefighters don’t have in one place.

Merritt: It surprised us. You know, we built this for the public that needed to know this information. And then we found out that, you know, during fires, there’s mutual aid where, you know, LA, all of the other counties nearby, and the firefighters drive down, but they don’t have good ways of sharing this information. And even within one firefighting organization, they don’t necessarily have the best tools. So, you know, it was sort of a side effect where we realized that this had become the de facto tool for firefighters to learn what was going on. We hear stories about, you know, all the pilots that are flying recon or air drops, they’re actually using Watch Duty for their most up-to-date information and mapping, which is, you know, we never imagined that, but it turns out it’s true.

McCarty Carino: I mean, the app relays incredibly granular data, you know, data on evacuations, on water drops, information from press conferences, kind of blow by blows of the firefighting effort, air quality data. Where do you get all this data and how do you push it out?

Merritt: Mostly we’ve been pulling in data sources that we ourselves use, and slowly over time, you know, when we first launched, it was just fire reporting, containment values, some pictures. And then we were like, OK well we need wind to make well-informed decisions. OK, let’s add a layer for wind. Oh, you know, [Air Quality Index] is going to matter to everyone that’s downstream from the fire. Let’s add that. Oh, here, you know, there’s perimeter data that’s available, but it’s published in a way that’s very, very hard for people to actually see. Let’s pull those disparate data sources in. So part of it is recording, and part of it is a consolidation of publicly available data that we sometimes clean and improve along the way to give people all the information that they need to make what’s a safe decision when they have time to do so, rather than waiting for an evacuation.

McCarty Carino: And I understand some of what you are calling reporting, this is being done by volunteers, right?

Merritt: Yeah. So we’re actually a mix now of paid staff reporters and volunteers. The reporters collect information, listen to radio — when we say reporters, the person writing the reports and updates that get to your phone — but there’s a huge team of volunteers that help support that. You know, during these LA fires, there were at one point, like, five concurrent fires that all needed pretty prompt attention. And that’s a lot. It’s, you know, we had people sleeping, not a lot, sleeping in shifts, even with a big team.

McCarty Carino: So monitoring all of the kind of radio chatter from all these first-response efforts and kind of transcribing that into the app?

Merritt: Yeah, exactly. So, you know, the heart of what they’re doing is listening to radio traffic, contextualizing that with what they see in cameras, what they get from other data sources, whether that’s people posting photos in our app to give additional context or other things that they’ve heard. We have a very strict code of conduct, so that’s why we like to use the term “reporting.” You’ll never see us saying what’s going to happen. We relay what has happened and what we’ve heard on the radio, but we’re not going to editorialize and we’re not going to make predictions because that’s an important distinction for us.

McCarty Carino: So this is really a pretty manual effort. It sounds like it’s not like you’re just pulling data sets from, you know, other sources, or, you know, populating data with automated systems.

Merritt: It’s very, very manual, and it’s an interesting partnership between technology and, you know, human reporting. Listening to the fire reporting, I mean, the radio scanning is very challenging. You know, the audio, it cuts in and out, it’s on different channels. And, you know, what we’ve tried to do with our organization is make something that’s both, you know, one half of it is the technology that allows the platform to work, and the second is giving the people that are good at that radio reporting a place to share the information that they understand and have synthesized. We don’t believe that we can automate away anything that they’re doing in a meaningful way right now.

McCarty Carino: And we should note here that the business model of the app is nonprofit, right? And it’s not sort of like relying on advertising or selling user data, any of that stuff. I mean, how does this work?

Merritt: Yeah, we kind of approached it from a “If you build it, they will come” business model, which may not work for everything, but as a nonprofit, we knew that we had something people really needed, and we were focused on building it and getting it to as many people as we can. And now we’ve started to gain enough momentum that I think we’ll be fine with just donations and grants, and that’ll cover what is really a very small operating budget. Most of our cost is salary, and you know, there’s some infrastructure and software costs associated with serving everybody, but it’s a pretty small marginal cost per person at that point. So we don’t want to sell data. You know, there’s other ways we could have approached it, and I think you know that shows as well in when you open the app. We don’t ask for a login. We don’t ask for your email. Everyone, 95, 97% of people have never entered anything that we could sell, which I think is unusual in today’s market.

McCarty Carino: The scale of these fires in LA has really been unprecedented in terms of just the massive population [affected.] You know, hundreds of thousands of people downloading your app at once. How did this challenge your operations?

Merritt: Yeah, I mean, I can speak to the technical side. It was a lot. You know, we had 2 million app downloads within the first two days. We had 8 million users that first week. You know, essentially all of our metrics for usage, peak usage went to about 10x. It just took some nights, you know. I think we were lucky that we’d done some prework on the technical side to be able to withstand that. And we’re really happy that we didn’t have an outage or degraded service at any point during the fires. And then on the operations side with the reporters, you know, it was all hands on deck, everybody was working overtime. You know, people put a lot of effort and time and sweat and tears into making sure that our coverage was continuous.

McCarty Carino: Do you have plans to grow and expand the app in the future?

Merritt: Yeah, you know, we want to expand to the rest of the U.S. It’s not really a technical limitation, but, you know, like we discussed earlier, there’s a lot of training, there’s a lot of onboarding of new people, and we want to maintain the same high-quality reporting anywhere we go. We’re not sure what it looks like exactly, but having surveyed other disasters that have happened in the U.S. and internationally, there is a gap of good technology solutions for emergency management and emergency disaster response that we think we can have a role in helping to fix. We hope to be able to find other places to focus our attention on, while still maintaining our core offering of keeping people abreast about wildfire information.