A 911 caller told police that a Connecticut woman had threatened to kill herself before her two children were found dead and she was found injured in a home filled with natural gas.

East Haven police have released a 911 recording of a friend of the woman saying she was outside the woman's house Tuesday, she couldn't get in and the woman said in a phone call that she had cut herself. The caller also said the woman had sent her a letter containing a suicide threat.

Authorities haven't released the names of the mother and her children.

A 5-year-old boy and his 7-year-old sister died, and the woman is being treated at a hospital for non-life threatening arm injuries.

Police believe the natural gas had been turned on deliberately.