AUSTIN, Texas (AP) — Suddenly, the "Keep Austin Weird" slogan doesn't feel so fun anymore.

The beloved local motto — repeated with equal pride by college students, self-proclaimed slackers, 20-something tech hotshots and high-priced lobbyists — isn't supposed to apply to something as sinister as the string of deadly recent bombings.

The blasts have sent a deep chill through a hipster city known for warm weather, live music, barbeque and, above all, not taking itself too seriously.

Could all that make Austin, whose population and economy are booming, whose politics are liberal and whose diversity is rich more likely to be targeted? No one really knows.

Police in the Texas capital are still working to determine a motive for the five bombings that have killed two people and wounded four others since March 2. The blasts have struck multiple locations, making detecting a pattern difficult.

The first three explosives were hidden in packages left on doorsteps, while a bomb that went off on Sunday used a more sophisticated tripwire. Another parcel detonated Tuesday at a FedEx processing facility in Schertz, about 60 miles from Austin, near San Antonio.

Investigators say the blasts could be acts of domestic terrorism or possibly hate crimes since the victims of the first attacks were all black and Hispanic, though the two men hurt in Sunday's explosion were white.

The package shipped via FedEx came from Austin and was heading back to an Austin address, but authorities have not divulged details about where it was going.

"For us, it's personal. This is our home," Police Chief Brian Manley said Tuesday. He noted that many crime statics still rank Austin among the nation's safest cities.

"We're facing a big challenge, and we will get through this," Manley said. "We don't want to lose, in the middle of all this, that we're still a safe city."

The population has grown from less than 800,000 in 2010 to nearly 930,000 two years ago, according to census figures and city estimates. Factor in suburbs that have sprawled past Austin's northern and southern limits and the growth is even faster. The expansion has been fueled by an increasingly large Hispanic community, which has helped make Austin more diverse.

Nelson Linder, president of the Austin chapter of the NAACP, originally suggested it was no coincidence that the first two blasts hit victims with ties to people active in Austin's black community. But Sunday's explosion involved a tripwire along a public trail that could have ensnared anyone. Now the entire city is watching closely.

"It got everybody's attention," Linder said. "No one is safe."

Austin is also a liberal bastion, happy to be the blue hole in the middle of the deeply conservative red doughnut of Texas. Its economic surge has been anchored by a thriving tech sector featuring companies like Dell, Samsung and Apple. Facebook and Google also have offices here, and there's a chance Amazon's coveted HQ2 could being coming as well.

Ken Herman, an Austin American-Statesman columnist with a wickedly dry wit who has lived in the city since 1979 except for five years when he worked in Washington, puzzled over the question of why.

"There's a lot of new people who come to town, and maybe they're not accepted in for some reason — although this is a fairly accepting community, even if you're from California," Herman said. "It could be someone who says, 'Austin isn't what it used to be.' Who knows? That's what so diabolical about this."

Austin has endured dark times before. It was still a sleepy college town in August 1966, when Marine-trained sniper Charles Whitman climbed to the observation deck of a clock tower on the University of Texas campus and opened fire in an attack that introduced Americans to the idea of a mass shooting.

Still, the bombings have not scared people into staying home or disrupted daily routines. Two bombs exploded during the South By Southwest festival last week, but the blasts were far from the main attractions. A PGA golf tournament begins Wednesday on the city's western outskirts, well removed from any blast site.

Austin is also home to the UT campus, one of the nation's largest universities, with about 50,000 students. Fall football games draw 100,000 fans. But no bombs have so far been placed near the university, and they have similarly spared the city's tech and entertainment districts.

Instead the explosions have hit nondescript suburban enclaves that could be neighborhoods anywhere.

Noel Holmes lives in the one where Sunday's bombing happened. She said the attack left her and many others simply shaking their heads.

"I'm hoping someone turns this person in," Holmes said. "Or that serial bomber will find another neighborhood to put the fear of God in."