DENVER -- For nearly three years, the CALL7 Investigators have been reporting on major problems within Colorado's child welfare system, specifically mistakes and mismanagement by the Denver Department of Human Services.

Despite promises to improve case management, enhance child safety and hire more caseworkers to help the already overwhelmed caseworkers at DDHS, two more children have died.

On Dec. 18, the CALL7 Investigators aired a comprehensive special report titled, "Children Failed, Children Forsaken." The half-hour special documented failures by DDHS that may have caused the two recent deaths.

Hosted by John Ferrugia, the investigative report briefly revisits four other preventable child deaths that were first reported by KMGH and it shows how one outside review after another found serious problems with Colorado's child welfare system.

Yet, in nearly three years, little has been done. For example, DDHS promised to hire 40 additional caseworkers to protect children, but CALL7 Investigators found the agency hired no additional workers but just replaced those who left.

Angel DeHerrera was 4 years old when he died at a foster home in El Paso County. He was playing on a trampoline in the backyard, apparently unsupervised, and was found strangled. His death was declared an accident, but prior to his death, DDHS workers knew there were serious problems at the home, and one caseworker had removed two people from that foster home just two days before Angel died.

The El Paso County District Attorney's office has reopened the case into DeHerrera's death.

"I ran in there and I dropped everything. I ran in the room and she was purple," said Dawn Ortega.

She was describing the day she found her infant daughter, Destiny Lewis, dead.

Lewis was three months premature and died after DDHS released her to Ortega, who admitted she suffers mental and emotional issues and could not care for her daughter.

Workers at two hospitals also expressed concern for the child's safety to DDHS, but in a written report obtained by the CALL7 Investigators, a case worker determined, "The [mother of the child] has skills and ability to parent her child safely." It continued, "No safety concerns are identified," and "No further safety action is necessary."

As a result of previous CALL7 Investigative reports, as well as a state audit of child welfare, Colorado Gov. Bill Ritter formed a Child Welfare Action Committee. The half-hour special highlights several recommendations made by the committee, including a statewide training academy for caseworkers.

"The kind of bold, dramatic reforms that are critical to keep kids safe have not been implemented," said one member of the committee, Shari Shink.

Shink is founder and executive director of the Rocky Mountain Children's Law Center.

"We now have two more preventable deaths. The signs are not subtle. The signs are major warning signs," said Shink. "We never resourced our system adequately since the last recession."

The CALL7 investigation continues.