HOUSTON -- An investigation is under way after two female firefighters found racist and sexual graffiti inside their HFD living quarters, and one day later, a racist message aired on a radio channel used by the city's firefighters, KPRC Local 2 reported Wednesday.

The city inspector general launched an investigation into the source of the racist message on the radio channel.

HFD spokeswoman Alicia White said firefighters heard the message on the Houston Fire Department's Trac 2 channel about 7 a.m. Wednesday.

Fire Capt. Otis Jordan, president of the city's black firefighters association, said that the broadcast contained a vulgar message aimed at black firefighters.

Fire Chief Phil Boriskie said the Houston Police Department is also investigating.

"Quite frankly, I'm mad. I'm mad as (expletive)," Boriskie said. "Someone or some group hijacked seven to eight seconds of airtime of a public safety-dedicated channel."

Boriskie said the message most likely came from an outside source.

Firefighters Jane Dreacott and Paula Keys said they found racist and sexual graffiti throughout their living quarters at Fire Station 54 on Tuesday morning.

The attorneys who represent the women said they want the Department of Justice and the Equal Employment Opportunity Commission to investigate the incident as a hate crime.

"There was graffiti on the walls, above their desks and all of their pictures, on their desks and inside their lockers. It was all defaced," attorney Elizabeth Pannili said.

Boriskie said it was a criminal offense and those responsible will lose their jobs.

Some close to Dreacott and Keys said the women recently complained about men urinating in the sinks and on the walls of their sleeping quarters.

"The message is clear: You're going to have to tolerate a sexist environment. You're going to have to try to get along with harassment. It goes along with being one of the few women at the station," attorney Joe Ahmad said.

The attorneys said Dreacott is particularly distraught. She found photographs of her daughter, who died in a car accident, defaced in her locker.

"They wrote the word 'die,'" Ahmad said.

Houston Mayor Bill White released a statement about the matter:

"Any form of racial or gender discrimination demeaning one group of people is unacceptable," he wrote. "We won't tolerate it in the fire department or anywhere else within the city. Before we judge and generalize about it, we need to get the facts and we will get to the bottom of it. I have confidence in the professionalism of the (Office of Inspector General) to do that."

Houston City Council member Jolanda Jones said a federal investigation is needed.

"I have a sister who lost a child. I cannot even imagine how it would affect my sister if someone wrote on my dead niece's picture, 'die,'" Jones said.

Dreacott and Keys said they will speak out publicly about the incident Thursday morning.