IRS website crashes on the last day to file returns (without an extension)

Just in time for tax day: the IRS website to make payments is down.
The IRS did not have an immediate explanation for the failure. But it said on its website that its online payment system became unavailable at 2:50 A.M. ET on Tuesday.
IRS Acting Commissioner David Kautter testified during a House Oversight Hearing Tuesday that a number of systems are down at the moment and that they are working to resolve the issue. (And Twitter reported outages worldwide if that offers the IRS any comfort.)
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