The trial of a Bronx school teacher accused of killing her two young children began Monday.

Prosecutors accuse Lisette Bamenga of killing her 4-year-old son and infant daughter on July 5, 2012, in an effort to get revenge on their unfaithful father.

The defense argues that Bamenga was not in her right mind when she committed the horrendous acts.

Investigators say the children died after Bamenga spiked their grape juice with deicing fluid -- a chemical compound used to melt ice and snow -- and then drowned them in a bathtub.

First responders testified in court Monday that they arrived at the family's Parkchester apartment and found the children unconscious and Bamenga with cuts on her wrists. They say they also smelled a strong odor of gas in the home.

Officials pronounced both children dead at the scene.

Bamenga's defense attorney says she was suffering from post-partum psychosis.

If convicted, Bamenga faces a maximum sentence of life in prison. Her lawyer says she will testify on her own behalf as a key witness for the defense.