Kanye West

Kanye West performs Wednesday night at SXSW. (Rick Kern, Getty Images / March 12, 2014)

AUSTIN, Texas — A drum kit stood assembled and cans of beer were piled in a bucket. But otherwise, the outdoor stage at Cheer Up Charlie's was empty Thursday afternoon, an unusual sight for the ordinarily bustling South by Southwest music festival.

Earlier that day, a suspected drunk driver had plowed through a crowd gathered in front of the downtown venue, killing two people and injuring 23 others, police said.

An annual conference that also includes portions dedicated to film and technology, SXSW brings thousands of people to downtown Austin every March — an estimated 325,000 came in 2013.

This year, the crowds have filled the city's nightclubs and convention center, as well as streets that in many cases are cordoned off to accommodate the influx of visitors and artists.

PHOTOS: Car plows into crowd at SXSW

The busy downtown area where the tragedy occurred is home to a number of establishments that routinely host SXSW events.

A bouquet of flowers lay at the base of a telephone pole near where authorities said the driver rammed through a barricade about 12:30 a.m. Thursday.

Jayda Luna, 21, said he was in line at Mohawk, a club next to Cheer Up Charlie's, when the car slammed into the crowd. "I saw bodies fly into the air, and there was blood, and it was unbelievable," Luna said. "It was the most horrifying thing I've ever seen in my entire life."

Yet later that day, and just a few blocks away, festivities seemed in full swing.

A production crew was preparing for Lady Gaga's heavily publicized concert Thursday night at Stubb's, a barbecue restaurant just down Red River Street from Cheer Up Charlie's. Panel discussions about songwriting and copyright law drew sizable crowds to the nearby Austin Convention Center.

At a morning news conference, SXSW chief Roland Swenson said organizers "feel an obligation" to go through with the festival, scheduled to last until Sunday. "It would cause more problems for people to show up and be turned away than to carry on," he said.

Austin Police Chief Art Acevedo echoed Swenson, telling reporters, "We cannot allow one individual to ruin a celebration of life, of music."

RELATED: 2 killed at SXSW: 'The most horrific thing I've ever seen'

Still, the incident comes amid widespread debate over the expansion of SXSW, which started in 1987 as a music-industry showcase for undiscovered talent but in recent years has attracted top-level pop stars and corporate brands eager to reach an audience of perceived opinion-shapers.

On Wednesday night, Jay Z and Kanye West played a packed concert sponsored by Samsung, and Friday the rapper Pitbull is to perform with the backing of Apple's iTunes.

Other events slated to take place in the coming days include shows Friday and Saturday nights at the Doritos #BoldStage, a stories-tall mock-up of a vending machine.

Workers at a Ray-Ban promotional booth near Stubb's on Thursday afternoon were offering free haircuts as they had the day before, while a group of festival-goers waited in line to get into an awards show presented by MTV.

On top of the crowds that register for the festival, more than 300,000 others descend on the city for its unofficial parties and showcases, many of which offer free alcohol and are not directly affiliated with SXSW.

There's even a Twitter account that goes by the handle South by Free Drinks, posting daily updates as to where one can score free alcohol.

Harry Thynne, drummer for the L.A.-based band Drop Tank, which was in Austin to play SXSW, said that given the size of the crowds and the amount of "free booze" offered at some events, he wasn't surprised that such a tragedy could happen here.