Two Vinita, Oklahoma, boys are being treated at a Texas hospital for second- and third-degree burns their mother said they got at day care. 

>>UPDATE: Police serve search warrant at boys' grandparents' home in connection with the burns

She told KOKI-TV that she dropped her sons, ages 5 and 7, at the Happiness Is a Learning Center day care on Friday between 8:30 and 9 a.m. She said when she picked them up after 5 p.m., the kids told her they’d been at a splash pad all day without shirts on while they played.

>> Click here to see images of the sunburns. (WARNING: GRAPHIC)

She said the kids developed severe sunburns, and after she took them to a hospital for treatment, they were taken to the Shriner’s Hospital in Galveston, Texas, with second- and third-degree burns.

The kids' grandfather was shaken up by the incident.

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KOKI talked to the Department of Human Services, which is investigating the case. Officials at the day care told KOKI that their lawyers told them not to give a statement.

The kids are expected to be in Texas for five more days.