(CNN) No matter how fortified their SUVs are or how many years of experience they have, storm chasers aren't immune from tragedy.
The deaths of three storm chasers Tuesday in Texas proved that point.
Kelley Gene Williamson, 57, and Randall Delane Yarnall, 55, were in hot pursuit of a tornado when their Suburban crashed with the Jeep of another storm chaser, Corbin Lee Jaeger, 25.
"It hurts so bad losing our best friends this way," said Billy Wade, a Missouri-based storm chaser who knew all three men.
"All of us chasers are really close. It's like a family."
But that family has grown to include not just researchers gathering valuable information for the public but also thrill seekers who put themselves and others at risk.
Experts say storm chasers provide valuable research for the government and help give increased warning times to residents near a tornado's path.
In the early days of storm research, forecasters had no lead time to warn people that a tornado was approaching. But storm chasers can place probes and sensors directly in a tornado's path, picking up data that can't be revealed from afar.
Now residents can get an average lead time of 13 minutes before a tornado comes, according to the National Oceanic and Atmospheric Administration.
But professional researchers say amateur chasers are making their jobs more dangerous.
Mike Eilts started chasing storms more than two decades ago. Back then, most people driving toward tornadoes were trained scientists, he said.
Eilts, who worked for the National Severe Storms Laboratory, remembered a close call when he sped away from a menacing tornado -- straight toward a dead end.
"The decision was either to get out of the car and jump in the farmer's yard," he said, "or to try and beat it."
His team chose the latter. They floored it and barely escaped.
These days, a different kind of sight makes Eilts turn around and head home -- not the ominous funnel clouds, but throngs of drivers parked on highway shoulders trying to capture the "money shot."
"I call it 'tornado zoo.' They think they can just drive up like it's a lion on the other side of the cage," he said. "They take a picture or video of it, not thinking that the whole thing can expand in literally seconds, a new suction spot can come out, and you have no time to react to that kind of thing."
Martin Lisius, who's been chasing storms since 1987, said he thinks the 1996 movie "Twister" spawned a generation of thrill-seeking storm chasers who have no idea what the real risks are.
"They're acting like they're in a movie," he said.
Chuck Doswell, one of the original storm chasers from the 1970s, said any unnecessary cars on the road can endanger everyone.
"There can be no doubt that simply being on the highways is a dangerous thing," Doswell wrote in an essay that many consider the premiere manuscript on storm-chasing etiquette.
He acknowledged that storm chasers "do several things that put us at risk."
"We often drive with less than 100% of our attention on the very important task of driving, we're prone to exceed the posted speed limits, we hurtle down rain- and possibly hail-covered highways, we make sudden stops, turns, and starts without much warning," Doswell said.
"Unfortunately, risky behavior, repeated often enough, can become a tragedy."
Lisius said some chasers seem to be motivated by fame, fortune or the hope that their video can land on television.
For years, CNN and other national news networks have purchased tornado videos shot by freelance storm chasers. The fees can be in the hundreds of dollars and even more than $1,000 for editorially important images
Eilts said he worries about a severe storm striking potentially thousands of people stuck in traffic jams caused by storm gawkers. Already, he said, professionals have a harder time collecting data, and emergency responders struggle to reach areas that are in danger.
"I think it causes a lot of problems for scientists that are trying to do their jobs, for scientists that are trying to get sensors in the right place," he said.
Lisius now runs Tempest Tours, a company that offers storm-chasing expeditions for tourists -- and a chance to photograph storms from a much closer vantage point.
"It's like a cruise," he said. "We have a schedule. We have a departure and return. We have a port city, which we call our base city."
These port cities don't have ocean views. Arlington, Texas; Oklahoma City; Denver; and Phoenix are among the spots where Tempest Tours take off.
But Lisius said he's not in the business of endangering tourists.
"It's all about education and teaching them about the atmosphere," he said. "It's not a thrill-seeking tour. That's not us."
Lisius said it's easier for a tour group watching a storm from afar to change course than it is for researchers.
"Our mission is to teach people about severe weather, and we can get close enough to a tornado to see it and take good pictures of it, but certainly we don't have to get in the path."
The growing number of amateurs makes storm chasing riskier, but deaths are still rare, CNN meteorologist Brandon Miller said.
"It's actually a miracle that it doesn't happen more," said Miller, himself a longtime chaser. "It's a ton of people distracted driving, paying attention to dozens of other things and not the road."
Before the deaths of three this week in Texas, Miller said the only other known instance of storm chaser fatalities came in 2013.
That year, Tim Samaras, his son Paul Samaras and Carl Young died chasing a storm in the Oklahoma City area.
NOAA said those deaths in 2013 appeared to be the first time researchers intercepting a storm's path were killed.
Now, the tightknit storm-chasing community is mourning again after the deaths of Williamson, Yarnall and Jaeger.
"It really hurts. All of us chasers are really close," Wade said.
Wade said he met the trio in Joplin, Missouri, where a tornado killed 160 people in 2011. They were there to pay their respects at an anniversary to remember the victims.
Wade grew so close to Williamson that he asked him to be a groomsman for his upcoming wedding.
"I know he will still be at my wedding in spirit," Wade said.
Shortly after his friends' deaths, Wade said he would honor their memories -- by going on a storm chase.