When we withdrew our 401k early, we already had our penalty amount withheld plus the 10%. Why am I getting taxes another 10% on top of the 20% I already paid?

I withdrew 10,389.49 from my 401k. They withheld 2,077.90-10% penalty plus the 10% taxes. Turbotax is also telling me that it's a 10% tax...I'm just confused.