It was 11:40 p.m. when the Titanic hit the iceberg. Captain Smith rushed up to the bridge.

At first, even Captain Smith thought everything would be fine. At 11:52 p.m., he sent a message to the White Star Line to say that his ship had hit an iceberg but that everyone was safe and he was heading for Halifax, Nova Scotia.

Passengers asked Officer Charles Lightoller if he thought the situation was serious.

“I tried to cheer them up by telling them ‘No,’ but that it was a matter of precaution to get the boats in the water, ready for any emergency. That in any case they are perfectly safe, as there was a ship not more than a few miles away, and I pointed out the lights on the port bow which they could see as well as I could.”

—Titanic officer Charles Lightoller

Some of the first reports of damage came from those Titanic postal clerks, who reported water streaming into the mailroom on the G deck.

Soon after that, it became clear that soggy mail was the least of the crew’s worries. If the Titanic had hit the iceberg head-on, damage would have been limited to the bow. But because the ship tried to turn to avoid it, the iceberg scraped along the Titanic’s side, slicing through its steel plates in multiple places, flooding six of its watertight compartments. Those safety features had been designed so that the Titanic could still float with up to four of the compartments flooded. But not six.

As soon as the ship’s builder and captain learned about the damage, they understood what was about to happen. The Titanic was going to sink. So they prepared for the worst.

Right about now, you might be wondering about that other ship, the Californian. Hadn’t its wireless operator said it was pretty close to the Titanic when he sent that message about being surrounded by ice? And hadn’t Lightoller pointed out lights on a nearby ship when he was telling passengers that everything would be all right? Why wasn’t that closer ship coming to help?

The truth is, the Californian was probably closer to the Titanic than the Carpathia was. But its wireless operator didn’t hear the Titanic’s first distress calls. After Phillips responded to the Californian’s earlier call with that message to “shut up” because he was busy, the Californian’s wireless operator had taken off his headphones and shut down his equipment for the night. Wireless operators didn’t monitor their equipment around the clock back then. If they had, the Californian would have heard the Titanic’s first distress calls and might have been close enough to help.

But now the clock was ticking. The Titanic was going to sink in a matter of hours. It was time to start launching lifeboats.

LIFESAVING TECHNOLOGY

The technology that allowed the Titanic to send out its distress calls was fairly new at the time. In the 1830s, Samuel Morse had come up with a system of sending telegraph messages using dots, dashes, and spaces to represent letters of the alphabet. Those were sent via electrical pulses of different lengths—short ones for dots and longer ones for dashes. So, for example, one dot would represent E. One dash stood for T. A was dot-dash, and N was dash-dot.

Early telegrams had required wires, but by the early 1900s, Italian inventor Guglielmo Marconi had come up with a system for sending those messages wirelessly, via radio waves. American president Theodore Roosevelt tested the technology with England’s King Edward VII in 1903.

By 1912, the system was being used to send ship-to-ship and ship-to-shore messages. Without it, it’s likely that none of the Titanic’s passengers would have been rescued.