Nearly 100 people were being baptized in the region during late evening services on Holy Saturday, said Debbie Bosak, communications director for the Catholic Diocese of Gary.
Holy Saturday is the day before Easter and is believed to be when Jesus' body laid in a tomb.
Bosak said the organization of the service can vary by church but, typically, it begins Saturday night with the lighting of the Easter fire and Paschal candle.
There is a procession into the darkened church, Bosak said. The first readings usually are in darkness, then parishioners light their own candles with the fire.
There are more readings and the Homily before beginning the baptisms and confirmations, followed by the rest of Mass, Bosak said.
The entire service can take between two and three hours, she added.
As the newly baptized parishioners celebrate their first Easter in the Catholic faith, it also is a first for newly elected Pope Francis. He presides over his first Easter Sunday as head of the Catholic Church.