Georgetown Police Commander George Vyphuis said detectives are trying to determine who set off the deadly blast in the depot near the bustling Stabroek Market. Police have detained a shopkeeper at a roadside beverage stand for questioning. “Right now the area is still cordoned off as we try to figure out what exactly happened,” Vyphuis said. Police said the casualty was a handyman whose head was blown off by shrapnel from the grenade.