The 'top hat' oil spill container. BP built the second, smaller dome after a larger vessel developed glitches Saturday. CNN

By H. JOSEF HEBERT AND HARRY R. WEBER (AP) ON THE GULF OF MEXICO — BP says a second, smaller container has reached the seafloor, but it hasn’t yet been placed over the blown-out well fouling the Gulf of Mexico. BP spokesman Bill Salvin said Wednesday that the 2-ton box had reached the seabed overnight. He says it hasn’t been positioned over the well yet because engineers want to make sure everything is hooked up correctly. Officials want to avoid the same icy, slushy buildup that thwarted their first attempt at using a much larger box that weighed about 100 tons. This box will be connected to a ship on the surface by a pipe-within-a-pipe when it’s lowered. Crews plan to pump in heated water and methanol so ice won’t build up. Salvin says undersea robots will position the box over the gusher by Thursday.

BP: 2nd, smaller container reaches Gulf seafloor