The all-out effort of the Terre Haute Police Department to solve the explosion last Tuesday at the YWCA in which the janitor, Carl Ross, 63, RR 6, was killed is being pressed by the department. Meanwhile, reports from the FBI laboratories at Washington, D. C., on the analysis of the blast debris and “foreign objects found in Ross’ body” are expected to be received this week. Chief of Detectives Willard Gantz is in charge of various in vestigation teams appointed to the case by Police Chief Frank Riddle. No new clues in the case were disclosed Saturday by the local officials. However, Chief Gantz pointed out that all possible ex planations of the explosion are being investigated. Murder remained as the most prevalent theory in the baffling case.