Two days after cellular and internet service abruptly vanished for most of Gaza amid a heavy Israeli bombardment, the crowded enclave was coming back online Sunday as communications systems were gradually being restored.

That's a welcome development for Gaza following a communications blackout that began late Friday as Israel expanded ground operations and launched intense airstrikes that illuminated the night sky with furious orange flashes. A rare few Palestinians with international SIM cards or satellite phones took it upon themselves to get the news out.

By Sunday morning, though, phone and internet communications had been restored to many people in Gaza, according to telecommunications providers in the area, Internet-access advocacy group NetBlocks.org and confirmation on the ground.

Read: Israel steps up air and ground attacks in Gaza and cuts off the territory's communications

After weeks of a total Israeli siege, Palestinians in Gaza felt the vise tightening. Social media had been a lifeline for Palestinians desperate to get news and to share their terrifying plight with the world. Now even that was gone. Many were consumed with hopelessness and fear as the Israeli military announced a new stage in its war, launched in a response to a bloody cross-border attack by Hamas on Oct. 7, and troops crossed into Gaza.

Exhausted and afraid her link to the world was so tenuous it could drop at any moment, 28-year-old Palestinian journalist Hind al-Khoudary said the massive airstrikes that shook the ground exceeded anything she had experienced over the past three weeks or any of the four previous Israel-Hamas wars.

“It was crazy," she said.

Residents on Saturday darted across dilapidated neighborhoods under heavy bombardment to check on loved ones. Medics chased the thunder of artillery and bombs because they couldn't receive distress calls. Survivors pulled the dead from the rubble with bare hands and loaded them into cars and donkey-drawn carts.

“It’s a catastrophe,” said Anas al-Sharif, a freelance journalist. “Entire families remain under the rubble.”

Reached by WhatsApp, freelance photojournalist Ashraf Abu Amra in northern Gaza said panic and confusion surrounded him.

“It’s barely possible to send this message,” he said. “All I want to convey is that the international community must intervene and save the people of Gaza from death immediately.”

Local journalists posting daily on social media scavenged the 360-square-kilometer (140-square-mile) territory to find even a spotty connection. Some moved closer to the southern border with Egypt, hoping to pick up that country's network. Others had foreign SIM cards and special routers that connected to Israel's network.

Mohammed Abdel Rahman, a journalist in northern Gaza, kept track of Israeli airstrikes all night, noticing the raids were concentrated along the strip's northern border with Israel.

Read: Parts of Gaza look like a wasteland from space following relentless Israeli bombing raids

“A new bombing is happening right now as we speak,” he said, as the roar of explosions resounded in the background. “There is an explosion, gunfire, and clashes are heard near the border."

“We do not know if there are (dead) or wounded because of the lack of communication,” Abdel Rahman added.

When the pace of bombardment slowed Saturday morning, residents rushed to the homes of loved ones with whom they had lost touch overnight.

“People right now are walking, using their cars because there isn’t internet," al-Khoudary said. “Everyone is checking on us, seeing us, and now we are going to check on others.”

She went directly to Shifa Hospital, Gaza’s largest, where doctors, exhausted from operating on patient after patient with dwindling fuel and medical supplies, pressed on, despite the crowds of some 50,000 people sheltering in the compound.

The wounded poured in from Shati refugee camp in Gaza City, al-Khoudary said, where Israeli bombs wrought destruction the night before.

Health authorities in Gaza and U.N. agencies warned that the blackout has exacerbated Gaza's humanitarian crisis.

Gaza’s Hamas-run Health Ministry said the communication outages had paralyzed an overwhelmed health system. As ministry spokesperson Ashraf al-Qidra addressed reporters at a press conference livestreamed by the Al Jazeera satellite network from the hospital, an older bespectacled man positioned himself just behind the podium.

While al-Qidra spoke, the man waved into the camera and pointed his hands upward to the heavens — apparently hoping to reassure someone far away that he was alive.

International aid organizations, whose limited operations inside the enclave have teetered on collapse, said they couldn't reach their staff nearly 24 hours after the blackout.

The chief of the U.N. Palestinian Refugee Agency, Philippe Lazzarini, penned a public letter to his staff in Gaza expressing “immense worry” for their safety.

Read: Israeli troops launch brief ground raid into Gaza ahead of expected wider incursion

“I am constantly hoping that this hell on earth will soon come to an end and that you and your families are safe,” he wrote. “You are the face of humanity during one of its darkest hours.”

Doctors Without Borders said the group had not communicated with its team in Gaza since since 8 p.m. Friday.

“We are not able to send our team to different facilities because we have no way to coordinate with them,” Guillemette Thomas, the regional medical coordinator, said from Paris. “That's really a critical situation."