My son died from a drug overdose. Here is his toxicology report Cocaine 0.05 Threshold? THC 14 Threshold? Xanax 0.05 Threshold? Diazepam .03 Threshold? He went into cardiac arrest and coma. He had no brain activity for 72 hours. Taken off life support and never started breathing on his own. Please explain the drug quantities in his system and what caused cardiac arrest. Thank you. This is a forensic lab report e-mail is YYYY@YYYY