"Engine 56 we have a code blue 7405. We need police code 3,” shouted a Dallas firefighter.

At 11:45 p.m. Saturday, Dallas police and firefighters were called to an apartment complex in the 7000 block of La Cosa Drive for an urgent domestic violence call.

Sources said the victim told the operator, “She has a protective order against her husband and he is at listed location. Suspect has lighter fluid and was burning things in front of the apartment."

That is a priority one call, which means police should respond right away, but there were no officers available.

Dallas Fire-Rescue Engine 56 got there first.

Firefighters said the suspect came after them. Some of what happened was caught on Broadcastify audio.

"We are being chased by a guy with a knife,” a firefighter shouted, according to the audio.

Firefighters were being chased, so they ran to lock themselves in the fire engine and called DPD for help.

"We were attempting to leave the scene," a firefighter said. "Suspect jumped in engine."

Firefighters were able to hold the suspect down and again called DPD for help.

"We've got him held down. We need police code 3."

But no DPD officers were available.

“Can we get an ETA on police? Engine 56 we don’t have ETA on police. Engine 56 if you can let the guy go. Get in the engine and leave the scene the police have given you the ability to do that.”

“We are not letting go of this guy,” a firefighter said.

Sources told WFAA that officers were busy dealing with a stabbing nearby and a major car accident and there was no one who could help the firefighters.

Firefighters did not want to let the suspect go, because at one point they told dispatch he tried to stab his wife in front of them.

Desperate for help, DFR asked dispatchers to call Richardson police for assistance.

“We are about two miles from Richardson. Can we just request mutual aid so they can get here faster?”

Eventually, DPD arrived at 12:04 a.m., 18 minutes after the initial 911 call.

WFAA learned that the call held from 11:46 p.m. until 11:59 p.m., when it was finally assigned to a DPD officer. Once they were able to pick up the call they arrived within six minutes.

Editor's note: After the publication of the story, Dallas police released a statement explaining the timeline of the incident. Police are reviewing why the call was downgraded at the 911 center. Since the incident, a new directive from Dallas Fire-Rescue to its crew is effective immediately. All DFR crews will respond to calls of violent crimes, but will park a safe distance away and wait for Dallas police to show up.