Three men were killed after a car exploded on Saturday night in Allentown, Pa., prompting the evacuation of nearby residents, the authorities said.
Officials were investigating what caused the explosion and interviewing witnesses, but they determined by Sunday that there was no threat to the community, Tony Alsleben, interim chief of the Allentown Police Department, said at a news conference.
“Our investigation is leading us to believe that this was an isolated incident,” he said.
Scott M. Grim, the Lehigh County coroner, said three men were killed in the explosion, which was reported around 9:30 p.m. a few blocks from the city’s downtown. Officials were working to confirm their identities, and autopsies were scheduled for Monday, he said.
James B. Martin, the Lehigh County district attorney, said officials knew that a “criminal incident” occurred.
“We have a high degree of confidence that the perpetrator was probably killed in the incident,” he said. Officials released few other details, citing the continuing investigation.
The explosion took place on the edge of Old Allentown Historic District, a neighborhood known for its range of architectural homes, and near the city’s commercial and cultural hub for dining and shopping.
Stephanie Connelly told The Morning Call of Allentown that she was at a store when she heard an explosion that rocked the ground and reminded her of an explosion that left five people dead in 2011. In that episode, gas lines exploded, causing a fire that ripped through Allentown, and leveled homes.
Ms. Connelly said she ran toward the sound, where she saw a burning wreck of a car and flaming debris littering the street.
“I ran away, seeing body parts, and I couldn’t believe this is real,” Ms. Connelly said, sobbing. “This is real life and I’m shaking and freaking out while I’m running. I still can’t believe it.”
The authorities said surrounding blocks would remain closed as they continued to investigate. The Red Cross opened a shelter at a school for residents who were unable to return to their homes.