A two-year-old boy and a 74-year-old woman died after being rescued from a residential lake in Harris County, north of Houston, over the Fourth of July weekend, authorities said.

The double drowning occurred Sunday afternoon in a pond located in the Spring Lakes neighborhood, where emergency teams responded after receiving a report of two missing people.

Both victims were taken to a hospital, but doctors later confirmed their deaths, according to Click2Houston.

They went for a walk and didn't come back.

According to the Harris County Sheriff's Office, the boy had gone that day with his mother to visit the 74-year-old woman, who was a relative of the minor, although authorities have not specified the relationship.

The investigators indicated that the little boy became restless while he was in the house, so the woman decided to take him for a walk to a nearby park.

Noticing that both were slow to return, the mother went out to look for them.

That's when he arrived at the lake and found emergency crews performing cardiopulmonary resuscitation (CPR) on the woman. Shortly after, rescuers located the child in the water and also began attempts to save his life.

Authorities investigate how they ended up in the water

The woman was initially taken to the hospital in critical condition, where she later died. The minor was also taken to a medical center, but did not survive.

Major Ben Katrib, of the Harris County Sheriff's Office, explained that detectives are reviewing security cameras from nearby homes and interviewing neighbors to reconstruct the last movements of both victims.

Authorities also reported that the mother told investigators that her son could have autism spectrum disorder, although they stressed that it has not yet been determined how they both ended up in the lake.

Investigators stated that there is no evidence of a criminal act and that the case remains under investigation.

Neighbors ask to reinforce security in the area

Neighborhood residents described the event as an unprecedented tragedy in a community considered quiet and family-oriented.

One of them, Agha Hussain, said he had never witnessed a similar incident and raised the possibility of installing protective barriers around the lake to prevent new accidents.

The double death occurred amid a series of incidents involving child drownings reported in the Houston area over the holiday weekend.

The authorities took advantage of the case to reiterate the call to increase surveillance of children near bodies of water.

"Anything can happen in the blink of an eye. Children must be supervised at all times," Katrib said.

According to the Centers for Disease Control and Prevention (CDC), drowning is among the leading causes of accidental death in young children in the United States, especially during the summer months.