13 Deaths in a month is not a "MYSTERIOUS MASS DEATH" issue, especially not when some died of old age or were eaten by pythons. Strange however is it that so many "DISAPPEARED", we have seen that before in the SONGKHLA ZOO and that didn't end well, now did it?
Chiangmai Night Safari is far from a famous or even nice attraction, it is run as a tourist attraction with zero conservation projects, no proper education program and started many years ago with the plans to even have a restaurant where people could eat wildlife. The place charges foreigner 4 times the local price, the animals are under bad care and don't get proper nutrition. Chiangmai already had a zoo and that should have been enough.