A man known to federal agents brought a gun to the White House and died in a shootout.

Secret Service agents killed an armed man at a security checkpoint Saturday evening after he opened fire near the heart of the government.

We expect the most famous house in the world to be the safest place on earth. But for a few minutes on Saturday, that safety vanished in a hail of gunfire.

WHAT HAPPENED

Just before 6 p.m. on Saturday, a man walked up to a security gate near the White House. He pulled out a gun and started shooting.

Secret Service agents fired back. They killed the man on the spot.

No agents or people nearby were hurt. The White House went into a total lockdown right away.

What the evidence shows

• The shooting happened at 6 p.m. on Saturday.
• The gunman had spoken to the Secret Service before this day.
• Agents killed the suspect during the exchange of fire.
• Zero bystanders or officers were injured.
• The suspect had a history of mental health issues.

THE BIGGER QUESTION

We often think of the White House as a fortress. But this man was already on the radar of the people who guard it.

If the government knew he was a risk, why was he able to get so close with a gun? We should ask if our safety systems are better at watching people than helping them.

THE OTHER SIDE

The search for facts will look at the man's past to see if he wanted to die or cause harm. His history of mental health issues suggests he may have needed help long before he reached the gate.

The evidence of an active shootout makes the use of force seem hard to avoid.

WHAT HAPPENS NOW

Safety rules around the White House will likely get even tighter. This means more closed streets and more guards for people in the city.

It also shows how hard it is to keep leaders safe when someone is set on doing harm.

WHAT WE STILL DON'T KNOW

1. How did the man get a gun with his health history?
2. What did he say to agents in the past?
3. Was there a specific event that triggered the attack?

SOURCE NOTE: Based on reporting from The Hill. All charges are allegations - the suspect is presumed innocent until proven guilty.