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11/01/2007

Three Months After Minneapolis: Examining Wi-Fi's Role Following the Bridge Collapse

On October 25, W2i hosted a 90-minute webinar focusing on the critical role the Wireless Minneapolis Wi-Fi mesh network played in supporting emergency responders after the I-35W bridge collapse on August 1st. Moderated by James Farstad, President of rClient, a trusted advisor to the city, a team of Minneapolis officials as well as representatives of USI Wireless (the network service provider) and BelAir Networks (the network equipment vendor) shared experiences and observations about the emergency response and the technology. The following is a summary of comments from the Webinar and is not comprehensive. Construction on a new bridge is expected to begin in early November.

Rob Allen, Deputy Chief of Police for the City of Minneapolis: "On August 1, 2007 at 6:05 PM, a large section of the I-35W bridge collapsed from causes that were unknown to us at the time of the collapse. The freeway section [bridge span] is 2,000 feet. The collapsed section was 450 feet and 113 feet above the water itself; 114 vehicles were on the bridge at the time, and 88 were passenger cars. The rest were construction equipment. It was a jurisdictional nightmare — a federal highway crossing a state bridge over a waterway....

"The city became the lead response. The fire department continued for 20 hours until police took over. The 911 center was inundated with 500 phone calls in the first hour, 50 of which were involved in the incident itself. Our primary focus was rescue of the injured. Fifty people were transported by ambulance in the first two hours. All told, there were 13 fatalities — 5 immediately and 8 recovered under debris over the next 19 days.

"One of our first priorities was to create a safety perimeter so our rescuers could operate safely. We did a complete survey of the scene. In the event this had been caused by something more nefarious, we sweeped the area with bomb dogs and techs. The initial perimter was 2.5 square miles and was large and complex. The main north-south transportation route through the area was blocked off. We were blessed to have good wireless connectivity through 800 Mhz. We did not co-locate police and fire commands, so we hit the networking hard and used the radio communications. Our Emergency Operations Center [in the basement of City Hall] was located off site.

"Initially we had received 1,200 reports of missing persons, so one of the key investigative jobs was to locate these people. One guy was in a rental car, climbed up the riverbank, got in the plane and went home. He never notified Hertz. We had to track him down and make sure he was okay. The good news is that within 48 hours we were able to get the number of missing persons confirmed. The bad news is those eight that were pulled form the river. It was very intensive and involved hitting cell-phone Web sites to find the last cell-phone pings from potential victims.

"With a perimeter of 2.5 square miles, we really relied heavily on mapping software which we were changing as we found new hazards. But GIS is bandwidth intensive, and our satellite service couldn't handle the bandwidth involved. Shortly after, we were able to get a node for citywide Wi-Fi, and [USI Wireless] were hammering the site in terms of bandwidth. We brought down a plotter, so we were doing four foot-by-six-foot maps, high resolution, and they were coming off the plotter as fast as when they were networked locally.

"We asked if we could hook up some video cameras to have a sense of what the scene looked. There was tremendous use of computing power during the event, and it saved us a tremendous amount of human resources by being able to use that."

Lynn Willenbring, CIO, City of Minneapolis: "USI Wireless, in the first 45 minutes, did open up the network to complete free public access, and they had approximately 1,000 users initially. But within a short period they had 6,000 concurrent sessions, including the emergency response staff and the public. In the next copule of hours, they brought some mobile trucks down to enable us to communicate with additional applications. Previously we were at 1 MB and were able to get 10 MB per second down to the site which was so valuable when we brought the GIS maps to that area. We were able to do a lot of data sharing that we hadn't been able to do.

"Running an incident of this magnitude by radios is how it's been done in the past and how it will continue to work, but the visual data that was added was a huge benefit. We have CAD for police, fire, and emergency medical services. As you can imagine, this was a primary route for emergency vehicles, and it was urgent that we close that. We used GIS to get that done. And the Wi-Fi network allowed us to push that bandwidth down to the communication site — to emergency responders for whatever mapping capabilities they needed.

"Two days later the First Lady was in, and the President was in the following day, and we had the Secret Service in town with all their needs. It's difficult to impress the Secret Service, but I think we did that....

"We could also recognize new capabilities. Video surveillance of the bridge would be very useful during the recovery efforts. So we were able to put three temporary cameras onto the collapse site and feed that into the EOC and Command Center site, broadcasting to a hidden Web page with the IP address. The cameras also had pan, tilt, and zoom. Our EOC is in the basement of City Hall, with no windows, but to have that direct sight onto the bridge site and recovery efforts was a tremendous benefit to our staff."

Kristi Rollwagen, Deputy Director of Emergency Preparedness, City of Minneapolis: "When we look at the jurisdictions — from federal to local — we had a collapsed structure, a land rescue, water rescue, a truck on fire, a hazardous materials site, and a lot of triage and transport of our patients off the bridge, and a severe emergency. We didn't understand the scale and impact of the emergency until we were a couple of days into it....

"That first night I served as Public Information Officer, for the first 12-24 hours. The inundation of the media was unreal. We underestimated the amount of inquiry, which came from a multitude of countries as well. National media was on our doorstep within in 12 hours. Having not only cellular capacity and instantaneous information available to us was imperative, along with the link from the EOC to the field.

"The ability to see the I-35W bridge site from our EOC was unbelievable. It's in the basement, it's not a very pretty room, and it was a good mile from the collapse site itself. Beside what I was seeing on TV, I did not make it to the bridge until 3 AM the next morning. It was another set of eyes from a remote site and gave us a real idea of the issues going on. You could actually visually see what they were talking about instead of figuring it out in your own mind. We would see something remotely that was a safety issue and we could point that out instantly.

"The ability to prioritize equipment resources going forward, as we went into the body recovery, was amazing. It helped us prioritize because we knew we wouldn't see this equipment — large cranes moving up the waterways from large cities. I can't tell you how they found a barge-mounted hazardous-materials truck, but they did. We operated on a PTAC 800 Mhz, and to have a visual to go along with that was unbelievable.

"For five years, we were successful because of the relationships in this room and outside this room. Without that we would not have been able to pull this response together. I'm proud of the folks because you looked around and knew everybody.... The last piece [of the bridge] was pulled out on Day 72. We turned it over to the design-and-build contractor in 70 days."

Kurt Lange, Vice President, USI Wireless: "When the bridge went down, and after getting over the shock, we wanted to know what value we could add — what could we do — so we placed calls to the city to tell them, "we're here." We then opened the network to the community, because cell networks were jammed, and the network could let people use media other than the cellular network. It went from 1,000 subscribers to 6,000 subscribers. We also used our portal capture page to provide feedback about what was happening at the scene as well as link to other emergency response systems. For example, you could look up how to donate blood.

"We opened up the network, and that made some difference in getting some communication happen around the city. We then got a number of calls about providing video access at the site. We were able to Wi-Fi-enable those cameras. That is not a simple effort because it wasn't necessarily powerful, so some augmenting had to be done. The river is actually a border for us. We had access on one side of the river but not the other. We had to deploy on the other side of the river and get power to them. The city had brought down some generators, and we were able to use some of the resources that were available.

"Traffic was a huge issue. There was a lot of emergency response, media, and community interest. We did station install crews with the equipment so we could quickly deploy as the need changed in a certain area. Having the necessary parts in the area, having the good communication, all played into getting this up and running. The city and the county had boats in the water where they needed access to information. They had people walking up and down the banks of the river needing access, which is why the wireless technology played a critical roll in the effort. We were fortunate to deply more of the network there because the wireless was adaptable in that area. Kudos to BelAir and the City.

"This has transitioned to what was a temporary solution to a long-term solution. The city wanted to keep those cameras there to monitor the site for safety and security and for the upcoming buildout of the new bridge. What started out as a disaster is a new phoenix of the bridge developing out of the old one. I think the value of the mobile broadband for public safety was high. We were able to bring a lot of bandwidth down that was able to meet the need. We wanted to try to provide some value in this time of crisis, and we felt the network was the right type of network to meet this type of need. It's not an exercise that you want to go through. It was a horrible thing that happened. The collapose was shocking, but part of the reason you deploy a wireless Internet network is for this type of disaster. In this case, it clearly seemed to meet everybody's needs. We were happy that we were able to do something at this time and provide some extra value to the community as a whole."

Jim Freeze, Senior Vice President, Marketing and Alliances, BelAir Networks: The infrastructure must support lots of capacity — not 200–300K but multiple megabits of capacity — which becomes truly important during an emergency. And the network must be multiservice, from data to voice, high-fidelity and video. It's not just about Wi-Fi, not only 2.4 Ghz but 4.9 Ghz, and the infrastructure must work with all of these.

"Mesh is important going forward, and the different meshes really matter. The mesh technology that most providers use in this space is a shared mesh, a technology that uses a single radio or frequency where all nodes broadcast on the same frequency or channel to all other nodes. While it works, it also means that all nodes are communicating on the same frequency and bandwidth, and the problem is that it starts to slow down and you can't support mission-critical applications because of latency, and there will be significant amounts of jitter (how packets travel and get back together). That shared mesh technology used in most vendors' technology won't work for video and voice.

"But BelAir uses a different architecture related to 'multiple radios' used to create massive amounts of capacity with very low latency, bringing massive amounts of capacity where it's needed and when it's needed. You don't want to find out you don't have carrier-grade service right in the middle of an emergency.

"Switched mesh architecture: We use a number of radios in a node — multiple radios, which provides a dedicated point-to-point link on an isolated channel, so when data is transmitted it happens over one of those connections. Low latency, low jitter — that translates into the ability to support key applications.... What you can see is that networks based on BelAir are performing 5 to 10 times faster than other networks. Others are challenged to support video and voice. They perform extraordinarily well because of the switched technology that BelAir delivers."

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Three Months After Minneapolis: Examining Wi-Fi's Role Following the Bridge Collapse

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