By Jeffrey Stein & Mike DeBonis @ Washington Post via ChicagoTribune.com, April 17, 12:36 pm

The Internal Revenue Service's electronic system that allows Americans to submit their tax returns online has partly failed Tuesday, complicating filing for the millions of taxpayers attempting to meet the government's midnight deadline.

"On my way over here this morning, I was told a number of systems are down at the moment," IRS Acting Commissioner David J. Kautter told lawmakers at an oversight hearing Tuesday. "We are working to resolve issue and taxpayers should continue to file as they normally would."

Kautter said the problem was "probably" the result of internal technical problems. But he said he did not know the exact cause and could not rule out external interference - including from a cyberattack.

The full extent of the failure could not immediately be determined. Kautter said the agency was struggling to accept returns from widely used software programs such as TurboTax and Intuit - as well as from H&R Block, the massive tax preparation company [....]