What should have been just another summertime music festival ended in shock.

The Mad Decent Block Party, an electronic dance music roadshow fronted by veteran DJ and producer Diplo, rolled into Merriweather Post Pavilion on Aug. 1 with a lineup that included the electro-punk act Sleigh Bells and dubstep DJ Flux Pavilion. It was the festival's second summer at the Columbia venue, where it had attracted thousands of young fans with the kind of ecstatic, bass-driven music that moves bodies.

By the time the music ended, more than 20 people had been hospitalized and a young concertgoer was dead.  Howard County police said Tyler Fox Viscardi, a 20-year-old University of Maryland student, died of a suspected overdose (autopsy and toxicology reports have yet to be made public); two days later, a 17-year-old male from Northern Virginia who had been at the concert also passed away.

After interviewing witnesses and those ferried out in ambulances over the course of that cool, cloudy day, police concluded that Molly -- a newly fetishized form of the old dance-world drug MDMA -- played a role. Like the music fans, it had been at the festival, swirling in the crowd.

No other musical genre currently embodies the tastes of young people like electronic dance music. As large-scale events such as the Mad Decent Block Party proliferate -- EDM festivals brought in $1.3 billion in 2013, a not-insignificant chunk of the genre's $6.2 billion in overall business, according to a report by the International Music Summit, an industry conference -- it has come with a string of highly publicized drug-and-alcohol-related deaths and emergency room visits. The drug that EDM prefers is Molly.

In June, a Boston show by Swedish mega-DJ Avicii, one of EDM's highest-earning and most recognizable names, was roiled by three dozen alcohol- and drug-related hospitalizations that Boston police have attributed to Molly. Electric Daisy Carnival, a three-day Las Vegas event that was one of the first large-scale U.S. dance music festivals, this year also counted one death linked to MDMA. New York City officials last year halted the three-day Electric Zoo dance festival after two drug-related deaths; last week, a 23-year-old man was charged with selling as many as 80 MDMA pills to one of the victims and his friends.

Molly -- a term increasingly being used by authorities and fans as a catchall for all types of MDMA -- presents a unique risk for users, according to several people familiar with the scene and drug use. Frequently sold in powder form, it's often mistakenly thought of as highly pure MDMA; in reality, it's just as often mixed with other drugs, and where someone might have once consumed a single MDMA tablet, users of powdered Molly don't necessarily know where to stop. A stimulant, Molly can affect the regulation of body temperature, potentially resulting in heatstroke, whether a user is in a club, arena or on festival grounds.

Despite the presence of undercover and uniformed police at all Merriweather Post Pavilion shows, the Mad Decent Block Party resulted in "the largest number of hospital transports for overdose" Howard County Police had seen at the venue this year, department spokeswoman Sherry Llewellyn said in an e-mail.

Little more than a week later, all eyes will be on the Moonrise Festival, a new, two-day electronic music festival that will rumble into Pimlico Race Course in Baltimore on Saturday. The festival, which aims to draw up to 30,000 dance-music fans each day from across the mid-Atlantic is slated to feature 90 acts, most of them DJs.

But even this new festival has a back story. Promoter Evan Weinstein was an organizer of long-running Baltimore dance festival Starscape, which met an unceremonious end in 2012 after the festival overwhelmed Baltimore and Anne Arundel County emergency response units. Baltimore officials said after the 14th installment of Starscape that they would no longer permit the event to take place in the city's Fort Armistead Park.

Illegal substances will be prohibited at Moonrise, and Baltimore Police officers, fire and medical personnel will be on site, says Caron A. Brace, a spokeswoman for Baltimore Mayor Stephanie Rawlings-Blake. There will also be so-called "cooling centers," with shade and access to water.

In a brief statement issued Thursday night, Moonrise organizers said they had also worked with consultants and additional promoters to arrive at a plan that included on-site physicians, private EMTs and ambulances.

With EDM seemingly at a crossroads, however, is that enough?

'Everyone's terrified to tackle the drug issue'

There is a period of remorse that follows such tragic events as those in Columbia and Boston, so brief that it frequently feels like a blip in the music itself, a microgesture before the bass drop. Often, it's acknowledged in not much more than 140 characters.

"[O]ur hearts go out to everyone impacted by yesterday's event. we are truly devastated," Mad Decent founder Diplo (whose real name is Wesley Pentz), tweeted on Aug. 2.

"Just hearing the awful news abt tonight," Avicii (given name: Tim Bergling) wrote after his Boston concert. "Its a terrible thing, I rly hope everyone is ok! My thoughts go to those affected & their families."

Electronic dance music, spawned in warehouses decades ago and long an underground subculture, still exists behind a shroud that doesn't permit discussions of drugs or the mood in the dance-music world following recent festival deaths. Several requests for comment from Washington-area dance music promoters for this story were declined; after speaking with The Post about the Moonrise Festival in May, organizers of the event did not respond to requests made this week, instead releasing the news statement.

"Everyone's terrified to tackle the drug issue, and that's what we have to do," said Missi Wooldridge, executive director of the group DanceSafe, which promotes safety and pragmatic drug education at festivals. "It's clear that prohibition isn't working, and people aren't staying safe," Wooldridge said. "I think, often, promoters and festival organizers, their hands are tied. They fear being liable for drug-related emergencies or deaths."

Still, with several highly publicized deaths in the past two years, some in the EDM community are beginning to address drugs, sometimes in indirect baby steps.

Organizers of the Electric Zoo festival, which will return this month to New York's Randall's Island Park, will now require concertgoers to watch a two-minute drug PSA while entering the gates. The video never uses the word "Molly," or even "drugs," but shows a young reveler reaching into a baggie of powder, and later sweating profusely and alienating a friend. It ends with the phrase, "Be Present. Avoid the risks."

Wooldridge, however, said the video is doing the opposite of what festivals need. "They're not addressing the issue. They're sensationalizing drug use. They're falsifying drug use. They're offending parents who have lost their children."

But it is certainly a statement, one that underscores that changes might be ahead for mainstream EDM events.

In 2013, members of the music industry formed the Association for Electronic Music, in part to address the current landscape of dance music. (On its advisory board are representatives of concert promotion powerhouse Live Nation, talent agency William Morris Endeavor, record label executives and festival organizers.) Among the issues that served as a catalyst for the group, said chief executive Mark Lawrence, is safety.

One of the group's first initiatives, slated to launch in October, Lawrence said, is a series of best practices for electronic music promoters. The aim will be twofold: to educate young people on drugs and alcohol, and to empower festivals to enact swift response and treatment for those who, as Lawrence put it, "choose to continue to consume."

Among the most eloquent, and perhaps forward, calls for change came this week from Seth Hurwitz, chairman of concert promoter I.M.P. and the operator of Merriweather Post Pavilion, after the Mad Decent Block Party. Noting that he himself is a parent, he wrote, "We can spend every minute of the day making perfect sense to our children regarding the obvious perils of drugs, but sometimes it is impossible to convince them that this is relevant to their world. Youth feel invulnerable.

"I wish that this new drug abuse epidemic was as simple as eliminating the type of concert these people like to go see.... We need to work on convincing kids that those pills they put in their mouth could kill them."

Vigilance, if not abstinence

"Drugs and alcohol have always been a part of dance culture," said David Fogel, founder of the Forward Festival, a small annual electronic music event that has taken place in D.C. venues since 2007. "I'd go on to argue they're a part of every subculture -- punk, jam bands, Pink Floyd, and even poetry.

"Abstinence," he added, "is always is the best and safest policy, but it's naive to think people aren't going to do drugs."

While drug incidents at high-profile music events continue to make headlines, a nationwide Centers for Disease Control survey of high-school students released this summer showed MDMA use was down, from 11 percent in 2001, to 6.7 percent in 2013. (The data rarely, if ever, breaks out Molly use.)

With the relative youth of the EDM fan -- most of those attending concerts are under the age of 25, with many of those who have died in their late teens and early 20s -- Fogel advocates vigilance among audience members and promoters, who he says should be "watching over people, not with an intent to bust people, but with an intent to help people."

Fogel will attend the nearly 30-year-old Burning Man experimental culture event this month in Nevada as a "ranger," a volunteer entrusted to keep an eye on the community and direct medical help to those who need it. Music festivals have also begun to enlist rangers, invite organizations such as DanceSafe and offer "chill-out tents" for those who need to take a break. "If you have enough conscientious people in a crowd, you can pick up on . . . when things are going wrong. It's important to get to people before it's too late.

"That," Fogel says, "is on the shoulders of promoters and event throwers."