On boarding day, Mario tries to get his brother Paolo a job as a steward on board Titanic to replace an absent steward in the First Class Dining Saloon. He gets in discussion with Fifth Officer Lowe. Second Officer Lightoller interfers and allows it.
The Sandini brothers board the Titanic and they immediately find a beautiful stewardess, who tells them where to go. Paolo keeps staring at her, and Mario has to pull him with. As they walk through the gangway, they pass the Maloney family, see a steward trying to open a locked cabin door, and hear a loud smash. It is revealed the steward got absent because Mario fed him drunk the evening before. Mario brings Paolo to his assigned station before heading to the boiler rooms, causing him to arrive late. The leading fireman immediately puts him to work.
He invites Paolo go the firemen's dormitories, where leading fireman Billy Blake immediately insults the steward. He and another fireman leave in laughter.
That Sunday night, Mario is shoveling coal in Boiler Room 6 when the ship heavily vibrates and water starts gushing in. Mario and the other firemen in the room are shocked. It doesn't take long for Captain Smith and Thomas Andrews to arrive on the scene and take a look at the damage. Mario and his collegues are removing the hot coal from the furnaces, letting them drop in the icy water to cool them. If the water hits the coal in the furnaces, it might cause a thermal explosion.
Andrews has horrifying news: Titanic is sinking. Mario looks at Smith, and his desperate look makes him nervous. A collegue wakes him up out of his daydream and he gets back to work. Suddenly Mario gets soaked by a new flood of icy water. He and the other firemen run to dry rooms before the watertight door closes. Two firemen are too late and start extinguishing the fires.
On his way up, Mario finds a load of Third Class passengers locked downstairs, mainly by Steward Turnbull. Mario struggles to open the gate, which results in that Turnbull drags him in and all passengers escape, but Mario is dragged away by 2 unnamed seamen. He is locked up in a storage cupboard, where he's shocked to find the Ritz Restaurant crew. Around 2:10 A.M., Paolo finds them, but the door is locked and the water is rising very quickly. Mario and Gatti's Restaurant crew are saved just in time by Paolo and Peter Lubov. They rush up to deck, where they find no lifeboats. Mario & Paolo jump off the ship and try to swim to safety, but they are separated.
Mario finds an overturned lifeboat, where Seaman Davis helps him climb on. Mario keeps desperately calling Paolo. The ship breaks in two, and Mario steps back into the icy water to look for Paolo. He only finds another seaman, and Davis drags him back on the boat. Another man calls for his help, but when he tries to offer help, the man pulls Mario back in the sea, thus failing to be pulled on board. Davis drags the man on the boat, and Mario crawls back up too. The three of them watch Titanic sink.
Soon after, the boat is filled with survivors. Davis pushes back another swimmer, but Mario recognizes him as the Second Officer and pulles him up.
Lightoller takes charge of the boat and they all struggle to keep it balanced. Jack Thayer also arrives at the boat, but Davis holds him off, saying there's no room for him.
When Mario Sandrini notices one of the men is dead, he is lowered away and Jack can come on board. Mario & Lightoller help him on.
Finally, rescue arrives. Mario, Lightoller, Jack Thayer and a few others are brought to a pontoon of lifeboats.