31.   But late Wednesday, that speculation came to naught as investigators tried to piece together what happened in the houseboat.

32.   But Reno also indicated that investigators were still trying to determine who was behind the bombing.

33.   Chief Harvard defended her department Thursday, saying that investigators tried to contact the lawyer for the witnesses by telephone and left a message that was not returned.

34.   Chief Stan Knee said Wednesday he could not comment on the shooting of Vences because investigators are trying to determine whether the shooting was necessary.

35.   Cavanaugh said investigators were still trying to determine whether there was a common racial motive in the church fires that have swept through the region.

36.   Childress said the digging has been difficult in part because the investigators have tried to avoid upsetting a railroad embankment that straddles the area.

37.   Company investigators are trying to find out what happened to the crew.

38.   Clark said Army investigators were still trying to determine why the helicopter crashed, but said there was no indication it had faced hostile fire.

39.   Collins said investigators were still trying to determine Saturday how Gonzalez had been shot.

40.   Congress back in session, but office buildings still closed, and investigators try to figure out how the anthrax was spread in the mail facility.