A trial opens this week for a wealthy stock trader charged with murder in the death of a man who was helping him dig a network of tunnels beneath his Maryland home when a fire erupted.

Jury selection is scheduled to start Monday for Daniel Beckwitt's trial in Montgomery County. The 27-year-old millionaire is charged with second-degree murder and involuntary manslaughter in the September 2017 death of 21-year-old Askia Khafra.

Prosecutors say Beckwitt recklessly endangered Khafra's life during his secretive campaign to build a bunker beneath his Bethesda home for protection from a nuclear attack.

Beckwitt's lawyers say Khafra's death was a tragic accident, not a crime.

Firefighters found Khafra's charred, naked body when they entered the burning home, which was littered with mounds of trash.