In the months leading up to the 36th Olympic Games, there were countless concerns about the health and safety of the athletes and supporters who would descend on Rio; understandably so, with an array of threats ranging from Zika and water quality issues to violent crime and terrorism.

That prompted Olympic officials and Brazilian government leaders to seek out the world’s most advanced health and security innovations in an effort to keep Rio’s millions of visitors as safe as possible during the two-week event – and much of that technology was provided by American businesses.

While several notable incidents took place outside of the confines of the Olympic arenas (most notably, the saga that continues to unfold with the four American swimmers), the Games wrapped up on Sunday without any major security breaches and no reported terrorist attacks (despite several credible threats). Some, if not much, of the credit falls on innovative technologies employed during the event. Here’s a look at some of the American and non-U.S. firms whose state-of-the-art solutions helped keep the nearly half a billion Rio visitors healthy and safe during the Olympics.

Dynamis (Fairfax, Virginia)

Courtesy of Dynamis

A small but rapidly growing government contractor in Northern Virginia, Dynamis provided innovative security and emergency response software to Rio officials for both the 2016 Olympics and the 2014 World Cup. Called COBRA, the platform helps law enforcement officials, first responders and other security personnel closely monitor public events that take place on a large scale, and it allows managers to see where those security personnel are located in real time. If an incident does occur – from a natural disaster to a terrorist attack or a radiation spill – the software helps teams identify the location and scope of the threat and coordinate their response, all from a single digital dashboard that can be accessed on computers or mobile devices.

The tool was originally built to help emergency personnel communicate and coordinate responses to potential chemical spills, but it has since been expanded for use during extreme weather events, large social gatherings like the Olympics and music festivals, and even for threat detection purposes on U.S. military bases. Over the past few weeks, Dynamis’s COBRA technology has helped officials keep a close eye on every single Olympic venue in Rio, including the Athletes Village.

“We’ve been honored to have such a real world impact on everything from our local community’s fire department, our nation’s military and their safety, and our international customers as they provide safety and security for world class athletes at the Olympics, World Cup, and more,” Brad Gardner, Director of IT Solutions at Dynamis, wrote in an email.

Qylur (Palo Alto, California)

Designed by Silicon Valley tech company Qylur, the Qylatron security system is billed as twice as fast as traditional airport security scanners, and was used these past two weeks to keep athletes and spectators safe in Rio.

Qylatron uses artificial intelligence in combination with x-ray technology and other sensors to detect explosives, drugs, radioactive material and other security threats. The machine is essentially an extremely high-tech scanner that screens an individual’s bags and belongings inside of what looks like a futuristic locker.

The International Security and Defense Systems has trained many of its officers patrolling the Olympics how to use the system in order to better protect spectators. This security measure is meant to be the future of airports, public arenas, and other high risk areas.

Logos Technologies (Fairfax, Virginia) and Altave (São José dos Campos, Brazil)

Courtesy of Logos

If you were in Rio or if you watched enough of the coverage, you may have spotted some peculiar white balloons floating above the Olympic arenas. These balloons were equipped with 13 high-resolution cameras that send images in real time to security and law enforcement officials working the Olympics.

Brazilian manufacturer Altave partnered with Virginia company Logos Technologies to supply Rio authorities with this innovative technology, which is called Simera. The balloons have huge potential for the future of security, too. Tokyo has shown interest for the 2020 Olympics, as has Qatar, which will host the 2022 World Cup. Simera has also been used at major public events, with uses for safeguarding ports, railways, and other logistics hubs.

“Until now, WAMI sensors have been used either to protect U.S. troops in Iraq and Afghanistan or have been tested for domestic law enforcement and border security,” John Marion, president of Logos Technologies, said in a press release before the Games began. “This will be the first time that this sophisticated technology has been exported abroad.”

SayVU (Tel Aviv, Israel)

What began as a student project at Ben-Gurion University of the Negev, SayVU has grown into a thriving technology upstart with a safety program that was deployed as part of the security operations at the Rio Olympics. With SayVU’s systems, an individual can send out a distress signal in the event of an emergency by shaking his or her phone, pushing the lock screen, hitting the selfie button, or speaking into the phone (even in lock mode).

The Israeli startup also established a special hotline for the Olympics that would allow anyone in distress to quickly alert the right authorities and summon help. With the app enabled, the platform has the ability to record voice, GPS, and other location information and automatically send it to an emergency hotline.

“The Olympics is a central platform to reveal our unique technology to the world,” SayVu CEO Amotz Koskas said.

Greenlid (Toronto, Canada)

Courtesy of Greenlid

For athletes traveling to Rio for the Olympics, one of the biggest concerns was the Zika virus. Greenlid, a savvy Canadian startup that makes mosquito traps from recycled paper, helped put some minds at ease by providing its innovative traps to the Canadian Olympic committee to help protect the country’s athletes during their stay in Rio.

Built to last six weeks and then decompose, the traps are filled with water and insecticide. These biodegradable mosquito traps are leak proof and odorless, making them an ideal choice for protecting athletes inside the Olympic Village and surrounding training areas. The company also does business in Australia, where the government uses the traps to fight off dengue fever.

For every trap purchased, Greenlid donates another to communities affected by mosquito-borne illnesses.

“It’s about taking extra precaution, any extra step against these mosquitoes,” Jackson Wyatt, co-founder of Greenlid, said in a recent interview with Toronto’s Metro newspaper.

Digital Globe (Westminster, Colorado)

Colorado-based DigitalGlobe uses geo-spatial data technology to help security authorities identify contingency plans for situational awareness, logistics, and more – an important tool these past weeks in Rio, as nearly 11,000 athletes and 500,000 patrons descended on the city. With the help of satellite technology, DigitalGlobe was able to create a series of 3D models before the events kicked off to help plan for potential security breaches, as well as to help steer crowds away from mosquito hot zones in light of Zika concerns.

“Security for global events requires rapid access to current, accurate, and complete geospatial information for enhanced contingency planning, risk management, and emergency response,” Daniel L. Jablonsky, General Counsel and General Manager for DigitalGlobe, explained in a recent interview.

Kinsa (San Francisco, California)

Note: This section ran in a previous story on technology for athletes in Rio. Read the story here.

Courtesy of Kinsa

Concerns over the Zika virus and other tropical diseases took center stage leading up to this year’s Games. Thankfully, a startup dubbed Kinsa has created a device that can help athletes stay healthy via the company’s Smart Stick Thermometer—the first app-enabled thermometer to be approved by the FDA. The device allows users to take their temperature and track symptoms regularly using the portable device, which also offers relevant health advice based on a user’s profile. It comes with a companion app that connects to an athlete’s smartphone so they can log temperatures over time and share their vitals with others.

In an effort to keep athletes safe, the company is providing U.S. Olympians with the device, free of charge. The Smart Stick Thermometer was also made available to all competitors’ companions at the 2016 Rio Games.

“As an Olympian, I know that staying healthy is paramount, and that collecting data is a key component for ensuring you’re in peak condition,” Raj Bhavsar, a 2008 bronze medal-winning American gymnast, said in a press release. “With the added concerns of Zika in Rio, I can appreciate what Kinsa is doing to help athletes stay on top of their health.”