EAST CHICAGO — The FBI is asking anyone with information about Wednesday's explosion at the U.S. post office that injured one person to call the federal agency.
The FBI can be reached at 800-225-5324 or via email at www.fbi.gov/tips.
The East Chicago post office at 901 E. Chicago Ave. was open for business the morning after an explosion, officials said. The explosion occurred inside the building, injuring one postal worker.
There was no disruption in mail service, and the single pipe bomb did not cause damage to the building, U.S. Postal Inspector Mary Johnson said in a statement.
The FBI is leading the investigation into the explosion, which was reported about 6 p.m. Wednesday, Fire Chief Anthony Serna said.
East Chicago firefighters remained at the post office until 12:05 a.m. Thursday, Serna said.
The female postal worker was transported to St. Catherine Hospital in East Chicago with minor injuries, according to the FBI.
Investigators were working to determine a motive and identify suspects, but there were no ongoing public safety concerns, FBI spokeswoman Chris Bavender said.
The FBI always considers whether an attack on a federal building could be an act of domestic or international terrorism, Bavender said.
The investigation still is in the early stages and that determination has not yet been made, she said.
The U.S. Postal Inspection Service; U.S. Bureau of Alcohol, Tobacco, Firearms and Explosions; Indiana State Police; Indiana fire marshal's office; East Chicago Police and Fire departments; Porter County Sheriff's Department bomb squad; Lake County Sheriff's Department; Hammond Police Department; and Crown Point Police Department assisted at the scene or are helping with the ongoing investigation, officials said.
An ATF spokeswoman confirmed agents from the bureau's Chicago field office responded to East Chicago, but referred all other questions to the FBI.
East Chicago Avenue between Melville Avenue and Huish Drive was closed to traffic during the investigation.
In a statement issued Thursday, the FBI reminded the public to immediately call 911 if they receive a suspicious package or mailing and also contact their local FBI office, as well as the U.S. Postal Inspection Service at 1-877-876-2455.