The church roof collapsed early Wednesday, Sep 30, while most of the attendees of the conference attendees were preparing to sleep.
According to the Nepal police, around 1,500 people gathered in the eastern town of Dharan for a Christian conference.
"The participants were preparing to sleep when the wall collapsed. Most of the victims were on the ground floor of the building," police inspector Mohan Bikram Dahal was quoted as saying in a news agency report.
"The wall was made of bamboo and it could not withstand the weight of the people," he added.
17 women and four women were killed in the mishap.