DALLAS (AP) — Three Dallas police officers were shot, including one fatally, and a suspect who emerged from a vehicle with a long gun was killed by officers after a highway chase, authorities said Friday.

Just after 10 p.m. Thursday, Dallas police responded to an officer in distress call and found a fellow officer wounded in a squad car, police said. The responding officers exchanged gunfire with the suspect at the scene and two of the officers were shot.

The three officers were taken to hospitals, where one of them died. The other two were listed in critical and stable condition, police said.

The suspect fled the scene and was pursued by other officers to Lewisville, Texas, about 25 miles (40 kilometers) northwest of Dallas, police said. The man then got out of the vehicle with a long gun on Interstate 35 and was shot by officers, authorities said. He died at the scene.

The identities of the officers were not immediately released.

“Dallas has lost a hero,” Dallas Mayor Eric Johnson said in a statement Friday.

He said officers do dangerous work with “grace, honor, respect, humility and extraordinary courage” so that “the rest of us can sleep peacefully.” He said the attack on the three officers “is nothing short of an attack on our city, our families, and our way of life.”

The investigation is ongoing, the Dallas police said, adding that flags at city facilities will be flown at half-staff.

”Our department is hurting,” department spokesperson Kristin Lowman told reporters early Friday. “We have officers who are injured, who are in the hospital, and we lost one of our own.”