(CNN) Four teenagers were able to escape through the front door of a Nashville, Tennessee, juvenile detention center because of critical oversights by the company that managed the facility, officials said Monday.

The teens, two of whom are accused of murder, fled the Davidson County Juvenile Detention Facility Saturday after being left unsupervised, police said.

Police say the company that manages the center waited more than half an hour after the escape before notifying police the four teens -- ages 15, 16 and 17 -- ran out the detention center's front entrance.

"In 30 minutes, with a fast walk you could be two miles away," Nashville Police Chief Steve Anderson said. The youths have not been found as of Monday night.

Youth Opportunity Investments, a private detention contractor which has managed the center since 2015, fired three of its employees and suspended one for three days in reaction to the escape, the company said.

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