AUSTIN, TEXAS — When Corazon Renteria heard a loud bang outside her Austin, Texas home Monday, she supposed an electrical transformer had exploded. 

She was wrong. 

The noise was a bomb that exploded about five houses from where Renteria lives, critically injuring an elderly neighbor.

“We’ve had transformers pop,” Renteria said. But this time, “Within five minutes, it was a slew of fire trucks, ambulances, police — more than a transformer,” she said. 

It was the second of two package bombs that exploded in Austin Monday. 

One person was killed and another wounded in the earlier blast.

“There are similarities that we cannot rule out that these two items are, in fact, related,” Austin Police Chief Brian Manley told the Austin American-Statesman on Tuesday.

The explosions are now believed to be linked to a March 2 explosion that killed one person.

All of the victims are minorities, but Austin Mayor Steve Adler said labeling the events hate crimes is premature at this point. 

As federal agents continued combing the neighborhood Tuesday morning, Adler stood at the taped-off intersection of Vargas Road and Galindo Street, talking to reporters. 

“We don’t know the answers to so many questions,” Adler said. “I’m confident that they’re going to be able to find out answers to what’s going on.”

Adler said the capital city has never faced such a series of crimes. 

“This kind of thing can happen anywhere,” Adler said. “I would repeat: Austin is one of the four safest big cities in the country.”

Austin has adequate law enforcement for the task of investigating the explosion and ensuring safety, even as the massive South by Southwest conglomerate of festivals brought throngs of visitors, including Sen. Bernie Sanders and film maker Steven Spielberg, to town in recent days, Adler said. 

Austin police are the lead agency, but Adler said he’s been assured that federal agents are “all over this.”

Meanwhile, Luis Deniz said he was watching TV when the explosion occurred. 

“It was loud, like a [car] crash,” said Deniz, 18, who lives on the corner of the next block. “I went around looking for clues.”

Carlos Bonilla lives one block away from the Galindo Street bomb site. 

The block where the explosion occurred remained sealed off and guarded by Austin police officers on motorcycles as of early Tuesday afternoon.

Even though he’s the mayor, Adler said he was not allowed to get close enough to see the crime scene himself.

But from his home, Bonilla can see the light towers investigators erected to work through Monday night.

He said investigators had been on the roofs of nearby houses — looking for debris from the bomb was his guess — as well as walking the streets of the modest neighborhood. 

The likelihood of another such crime being repeated in the  neighborhood — one that’s crawling with local, state and federal law enforcement officers in black windbreakers — is unrealistic, in Bonilla’s opinion.

But, Bonilla said, “this is terrible,” adding that the feeling of “un-safety hurts more,” than the actual threat. 

The victim of the second Monday bomb was identified as 75-year-old Esperanza Herrera.

Susana Almanza is president of the Montopolis Neighborhood Association.

“I feel nervous,” Almanza said. “I don’t want to have anybody else get hurt.”

The neighborhood consists mostly of one-story, single-family houses built in the 1960s. 

Longtime resident Lupe Jimenez, 60, lives a block away from the blast.

On his street, six American flags tower over the block on poles.

Jimenez hadn’t yet done so, but said he’ll be lowering his flag to half-staff.

John Austin covers the Texas Statehouse for CNHI LLC’s newspapers and websites. Reach him at jaustin@cnhi.com.