FBI Responds to Minneapolis Bridge Disaster

The FBI is sending an evidence response team and other personnel to Minneapolis in support of the investigation into Wednesday's massive bridge collapse.

The heavily traveled bridge, part of the busy Interstate 35 corridor, collapsed during rush hour shortly after 7 p.m. EDT. Authorities in Minnesota have confirmed four fatalities and have shifted the effort from a rescue mission to a recovery effort, with a dozen divers searching underwater. An estimated 20 to 30 vehicles are reportedly underwater.

The National Transportation Safety Board has taken the lead on the investigation and the FBI's teams will look for possible evidence of problems such as shoddy construction or faulty materials.

"We will provide whatever resources we have available if requested by the NTSB or the state of Minnesota," FBI Special Agent Richard Kolko said in a statement.

The FBI is dispatching evidence response team members from its Chicago and San Antonio offices.

The bureau took similar action after a bridge in the San Francisco Bay area collapsed in May after a tanker truck ran into the structure.

FBI officials tell ABC News that they have not seen any evidence suggesting a tie to terrorism or sabotage at this stage of the investigation.

Local officials suspect some sort of structural or engineering issue with the bridge.

The Department of Homeland Security, in addition to the FBI, has been in contact with state and local officials, who noted that there was some construction work occurring on the bridge, which had in recent days restricted traffic to one lane.

Chris Krueger, communications director for the Minnesota Department of Public Safety, told ABC News that the state's Department of Transportation road crews were doing routine surface work at the time of the collapse.

The FBI has also issued a warning about the possibility that criminals might attempt to exploit the bridge collapse catastrophe.

"In recent history, tragic incidents such as 9/11, Hurricanes Katrina and Rita and the Virginia Tech shootings have all prompted individuals with criminal intent to solicit for contributions for a charitable organization and/or a good cause," the FBI release said.

According to the FBI, individuals can protect themselves by ignoring unsolicited e-mails and staying alert that some of those messages could contain viruses or links to Web sites for fake charities.

The FBI urges anyone seeking to make a donation for relief efforts to give to an organization directly instead of sending money or personal financial information through an e-mail.

ABC News' Wendy Fisher and Yvonne Lai contributed to this report.