The deaths of the two boys are being treated as suspicious deaths, says Toronto police Detective Terry Brown.
Police spoke to a relative of the family. Both boys appeared in good health earlier in the day Sunday, according to Investigator Browne.
Detective Browne did not did not want to confirm the cause of the mother's fall.
He specifies, however, that nothing leads investigators to believe that someone was with her at that time. The fall was likely not accidental, he said.
The woman was seriously injured. She is due for an operation, says Detective Browne, but police have no fears for her life at this time.