A 3-year-old boy allegedly pushed by his aunt last week into Lake Michigan in the U.S. city of Chicago died over the weekend, according to reports.

Josiah Brown, who had been in grave condition and was not expected to survive since he was pulled from the lake last Monday, was pronounced dead shortly after 10 a.m. Sunday, according to the Cook County Medical Examiner's office.

According to prosecutors, video footage shows the boy's aunt, 34-year-old Victoria Moreno, taking Josiah to Navy Pier, pushing him into the lake and then watching him struggle in the water without trying to help. Moreno told people that she didn't know the boy and didn't know what had happened to him, prosecutors also said.

Thirty minutes later, the small boy was found by divers on the bottom of the lake but had suffered severe injuries. He was taken to the hospital in critical condition and died days later.

Moreno was charged last week with attempted murder after the incident. The Cook County State's Attorney's office did not immediately respond to a request from The Associated Press (AP) for comment about whether the charges against Moreno would be upgraded because the boy died.

Moreno, a resident of nearby Des Plaines, who was also charged with aggravated battery of a child under the age of 13 causing permanent disability, remains in Cook County Jail after a judge last week ordered that she be held without bond.