“A spike in natural gas levels were detected between 1:30 and 2:00 in the morning of Aug. 10 from address 4232 Labyrinth Road,” Ford said. Lonnie Herriott, 61, who was staying at that house, was killed. So was Morgan State University student Joseph Graham, 21. Seven others were injured. “It can’t be ruled out that improper or incomplete installation of the new HVAC system was the cause for the gas leak,” said a report that was released by the fire department. “It also can’t be ruled out that unknown person/s tampered with the gas piping the night before the explosion causing the gas leak.”