>> reporter: they are, norah. if all goes according to plan, this test should end about midday today. and throughout the night, engineers and scientists at the houston command center kept doing their calculations trying to figure out what the pressure levels inside this ceiling cap really mean. you can see the difference on the surface above the damaged well. the flames of the discoverer enterprise and q-4000 are out. the crude is not flowing, but there are concerns. >> i think we're to a point where there's enough uncertainty regarding what the meaning of the pressure is that we're seeing that we need to have due diligence moving forward. and we need to be careful not to do any harm. >> reporter: after the first 24 hours, the pressure level read 6,700 pound per square inch, an inconclusive reading that could mean so much oil has already flowed out that the pressure is lower than expected, or there is a leak underground.