BRANDON — The parents of a boy run over by his father in a Waffle House parking lot last month have now lost a second young child, this time to accidental drowning.

The 1-year-old boy drowned in his maternal grandparents' swimming pool on April 5, according to a Florida Department of Children and Families incident report. The names in the report are redacted, but Guillermo Montoya Rios confirmed the boy was his son when reached by the Tampa Bay Times this week.

The drowning comes less than a month after Rios, 29, ran over his 2-year-old son Jeremiah at the Waffle House at 1412 W Brandon Boulevard. On the night of March 12, Rios and the boy's mother each mistakenly believed the other had placed Jeremiah in the family's 2007 Chevy Tahoe after the parents and their seven children had dinner at the restaurant, the Hillsborough County Sheriff's Office reported at the time.

When Rios pulled out of a parking space, the Tahoe's right front struck the boy, causing severe head injuries. He was pronounced dead at Brandon Hospital.

"The family reports that a head count is typically conducted when the children are in the vehicle; however, a head count was not conducted at the time of the incident," a state incident report says. Names are redacted from the report.

Both parents were screened for drugs and none were found. The Sheriff's Office released Jeremiah's name and called the death an accident, though the investigation has not officially closed and the full report was not available this week. The family lived lived in Brandon at the time.

Twenty-four days later, on the morning of April 5, Rios and his family went to the grandparents' home in Hillsborough County to help with a yard sale, the report on the drowning says. The children's mother and the couple's six children, ages 1 to 11, were with them.

Later in the afternoon, the two older children were playing at the home's in-ground pool while the younger kids played with a hose closer to the house. Sometime after 7 p.m., everyone came into the house and the children changed into dry clothes. About 7:50 p.m., the family noticed the 1-year-old boy was missing. His mother found him unresponsive in the pool.

A family member performed CPR until paramedics arrived. The boy was pronounced dead at St. Joseph's Hospital.

According to a Hillsborough Medical Examiner's report on the incident, surveillance footage reviewed by a sheriff's detective showed the boy walking on the pool deck, then falling or jumping into the pool. The video shows the boy floating around for about three minutes, then he stops moving, the report says. The boy's heart had stopped beating by the time paramedics arrived.

Both parents were screened for drugs and none were found, the report says.

The drowning report notes there were two other open child welfare investigations into the family at the time of the incident. The details of the investigations are redacted, but one of the cases appears to be the March 12 death of the boy at the Waffle House. Another investigation was opened in Pasco County by child protective investigators in February, the report says.

The report notes the family was also investigated by child protective investigators in 2016, but the details are redacted.

The deaths are being investigated by the Hillsborough Sheriff's Office, which conducts child welfare investigations for the Department of Children and Families. Department officials declined to comment, citing the pending investigations.

Reached by phone Wednesday, Guillermo Rios said his sons' deaths were a private family matter.

Times staff writer Christopher O'Donnell contributed to this report. Contact Tony Marrero at tmarrero@tampabay.com or (813) 226-3374. Follow @tmarrerotimes.