It is absolutely possible. What to do? Pay the tax bill, then have the appropriate amount of taxes taken from your weekly/biweekly/monthly paychecks, so that this doesn't happen again.
Actually, there could be something wrong here.
For a married couple with no dependents their taxable income after their standard deduction and personal exemptions would be 29100.00
Tax on 29100.00 for a married couple is 3610.00, less the 40.00 telephone credit is 3570.00
So, if they are regular W2 employees with withholding, something is amiss:
1) The preparer did not input their withholding (stranger things have happened)
2) They claimed so many exemptions that virtually no federal taxes were withheld
3) One of them got a 1099 MISC
4) One of the took money out of a retirement account and didn't withhold enough
In any case, its possible that there was an error. They should double check it with another tax professional. I am leaning towards an error simply because of the income level.