Police in Detroit said that two homeless children froze to death while they slept in a van with their family on Monday, while the city’s mayor revealed that their mother had reached out to homeless services a few months ago.

Tateona Williams, the mother of two children who likely froze to death in a van, tells PEOPLE in an exclusive interview that she reached out to homeless services in multiple cities and states but could not get help before their deaths on Feb.

The children, ages 9 and 2, were found frozen to death on midday Monday in the Hollywood Casino Hotel at Greektown parking garage, police said.