The conflict between Israel and Gaza erupted into fighting after an attack by Palestinian militants

Saturday was one of the darkest days in Israel’s 75-year history, as the Islamist militant group Hamas launched a deadly surprise attack, targeting civilians and soldiers alike.

Here’s what you need to know:

Mass assault: The attack began early Saturday, with Hamas firing rockets into Israel; Sending militants across the border by land, air and sea; Calling on civilians to take up arms against Israel. The attackers are still wreaking havoc on Israeli territory more than a day later. As of Sunday afternoon, thousands had been injured, at least 350 people had been killed in Israel, and “dozens” of civilians and soldiers had been taken hostage.

At the scene of the accident: The attacks, including one that sent concertgoers running for their lives, were captured on camera. One video showed an Israeli woman being kidnapped, lifted onto the back of a motorcycle and taken away while her boyfriend was also kidnapped. Another clip showed the motionless body of a German-Israeli woman, identified by her braids and tattoos, being paraded around Gaza as onlookers chanted “God is great.” A person was seen spitting on her head as the car drove off.

the answer: Israel responded with air strikes targeting Hamas. Inside Gaza, at least 313 Palestinians were killed and more than 1,900 others were injured. The Palestinian Ministry of Health said.

Next war: Prime Minister Benjamin Netanyahu vowed that the country would “retaliate severely.” The highest-ranking Israeli army official responsible for activities in the Palestinian territories said that Hamas “opened the gates of hell.” It remains to be seen what the precise response will be, but statements by a military spokesman hinted that Israel may attempt to take full control of Gaza for the first time since its unilateral withdrawal from the Strip in 2005.

Intelligence gap: Whether intentional or coincidental, Saturday’s attack began 50 years later, one day after another incursion that Israel failed to predict, what is known in Israel as the Yom Kippur War. Israel has since spent billions of dollars to create one of the world’s most powerful security services, yet today it still grapples with the kind of infiltration of military bases, towns and kibbutzim that characterized the 1948 War of Independence.