First, the Kan administration's favorite Yomiuri Shinbun (4/26/2011):
According to TEPCO, [Reactor 1] building's outer walls were severely damaged by the hydrogen explosion on March 12, but there is no discernible water leak on the Containment Vessel...
Never mind that the hydrogen explosion only blew up the 4th and 5th stories, above the Containment Vessel.
Now, not so favorite but still major news Mainichi Shinbun (4/26/2011):
Also, TEPCO disclosed on April 26 that the survey by the robots inside the Reactor 1's reactor building could not pinpoint the location of the damage on the Containment Vessel.
But no matter. TEPCO and NISA are going with their "accidental entombment" and about to gradually pour over 7,000 tons of water in the Reactor 1 Containment Vessel.