(CBS) — The sheriff in Waller County, Texas — where authorities say a 28-year-old Naperville woman hanged herself Monday morning — tells WBBM that jailers violated state rules by not checking on the detainee in person.

Waller County Sheriff R. Glenn Smith tells WBBM that jailers saw Sandra Bland at about 7 a.m. Monday morning.

“But at 8 o’clock they talked to her on the intercom. They did not physically go down there,” he said Friday. “And that’s wrong. That’s a violation of the jail commission rules.”

In fact, the Texas Commission on Jail Standards has now concluded that the jail violated that rule and also failed to train staff properly.

Smith says he understands how Bland’s family feels in wanting answers and questioning whether she really did commit suicide.

“I’d be highly concerned, highly upset that I lost a family member,” he said. “I think it’s still going to show just a tragic incident occurred with her there in the cell by herself.”

Smith says Bland’s behavior did not set off any red flags in the days or hours before her death. The jail inmate was allowed into another area of the facility to make phone calls.

“It was a shock. She was doing OK, she was fine,” the sheriff says.

“I can assure you that this has been devastating to the staff,” he added.

Sandra Bland’s family has been planning a meeting with officials in Texas.