Israel’s bomb shelters are last line of defense as Iran strike looms

TEL AVIV—When air-raid sirens sound, Israelis all know where to go—a system of bomb shelters dating back five decades that are built to withstand most conventional missiles.

This familiarity partly explains the mood in many Israeli cities, where people are nervous but not panicking as a promised attack from Iran looms. Summer activities for children are in full swing, and grocery stores are fully stocked. The military has placed no limits on public gatherings and are telling people to go about their daily lives. Bomb shelters in some cities aren’t even open yet.

Israel’s main defense against a potential missile attack by Iran and its proxies in the region will be the country’s multitiered air-defense system. It has a stellar record and, together with help from the U.S. and other allies, shot down 99% of the more than 300 missiles and drones fired at Israel in April by Iran in its first direct attack on the country.

Israelis are also relying on the bomb shelters designed to protect civilians from attack and built up and improved over the country’s 76-year existence. Many are putting their faith in it. “There could be real chaos,” said Ofer Shabtay, 39 years old, a programmer who lives in Tel Aviv. “But I feel very safe.”

Starting in the 1970s, Israeli cities began building a system of public underground shelters to protect residents from aerial bombing.

In 1991, Iraq, then led by Saddam Hussein, fired dozens of Scud missiles at Israel, hitting and damaging cities such as Tel Aviv and Haifa.

The next year, Israel passed a law mandating bomb shelters in every new building.

Today, around 65% of Israelis have a room in their home or apartment that is a bomb shelter, or have a bomb shelter on their floor servicing several apartments, or live near a public shelter, according to an Israeli security official.

Bomb shelters in apartments are made of reinforced concrete and heavy metal doors. Aside from the door and a fortified window, they are largely indistinguishable from a regular room. Many Israelis have turned them into their children’s bedrooms, so the children are safer when sleeping.

Since the early 1990s, these shelters have predominantly protected Israelis from short-range rockets fired from Gaza or Lebanon. Now Israelis are facing the prospect of cruise and ballistic missiles with significantly larger warheads fired from thousands of miles away.

According to the Israeli security official, the current infrastructure should protect Israelis from long-range missile attacks, since they were designed to withstand the blast and shrapnel produced by Scud missiles from Iraq.

Shelters in apartments are designed in such a way that even if the building collapses, they should remain standing as a separate fortified tower. A direct hit on the shelter itself would likely kill those within, the official said. But, the official added, that would be unlikely given the small surface areas of the in-house shelters.

Around a third of Israelis don’t have a bomb shelter in their building or live close enough to a public shelter to get to one before a missile or rocket would land. These are largely people living in poorer areas, including in the countryside, communities of Israel’s Arab minority, and lower-income neighborhoods in cities where buildings were constructed long before shelter regulations went into effect.

Israelis in the densely populated Tel Aviv area, located in the center of the country, have around 60 seconds to get into a shelter once they hear a rocket siren. Those living on the borders near Gaza or Lebanon have as little as 10 seconds to find shelter.

In Tel Aviv, Israel’s economic capital, there are 168 underground public bomb shelters, and 356 altogether if those at educational institutions or other municipal buildings are included. Their locations are available on the city’s website, and orange street signs inform people how to get to them.

A medium-size public shelter is about 100 square yards and can comfortably fit around 200 people in spartan accommodations. They have bathrooms, a small kitchen, a shower and air-filtration systems. Recently, the city began adding Wi-Fi to some of the underground shelters. Those in aboveground shelters, the most common type, usually have internet connections.

Inside, people usually check through social media to see where the rockets are landing.

They are also surprisingly social places, where neighbors or future romantic partners can meet for the first time. People are supposed to stay in shelters for 10 minutes after the last siren, but that doesn’t stop some from stepping in and out sooner.

Despite the threat of an imminent aerial attack, underground shelters around Tel Aviv are currently locked.

Municipal officials said that until the Israeli military gives the order to open shelters because of an imminent threat, they will remain locked. Signs on the doors say they will automatically unlock when sirens in the city go off.

This system, though maddening to some residents, is meant to prevent people from sleeping or defecating in the shelters, a common phenomenon before the system was put in place.

Shabtay, the Tel Aviv programmer, said he and his neighbors recently asked the municipality to unlock the public bomb shelter below their building. It was open for a day, but to their surprise, it was locked again the next day.

Many in Israel have been stocking up on bottled water and canned food in anticipation of an Iranian attack. Israel’s home-front command recommends having a few days’ worth of food and water as well as medical equipment in private bomb shelters or shared shelters inside residential buildings. Citizens are responsible for stocking them. The public shelters have an emergency water source, but no food.

Shabtay said he hadn’t loaded up on water or food. He did, however, take out cash.

Shachar Zivoni, 26, who was one of many people sitting outside a cafe in Tel Aviv on Tuesday night, said she hadn’t stocked up on bottled water or other goods. “Buying water makes me feel nervous,” she said. “I prefer not to buy and hope things will be fine.”

A friend sitting next to Zivoni, who declined to give her name, said she had no bomb shelter in her building and didn’t know where the closest one was.

“I just go to the stairwell and hope for the best,” she said.

Anat Peled contributed to this article.

Write to Dov Lieber at dov.lieber@wsj.com