The famous case of Donoghue v Stevenson was the basis of modern negligence law. In 1928, Mrs. Donoghue and her friend were having a bottle of ginger beer, which her friend bought. The bottle was not transparent, so Mrs. Donoghue couldn’t see inside.
After taking a sip, she noticed a very odd taste. Upon looking, she found a decomposed snail in the drink. She became sick, both physically and mentally. But per the law of the time, she couldn’t sue the beer manufacturer since she had not bought the beer herself. There was no contractual relationship between her and the manufacturer.
That’s when Lord Atkin established the “neighbour principle”, that one must take reasonable care to avoid acts or omissions that could reasonable be foreseen to injure one’s “neighbour” i.e. anyone closely and directly affected by the act.
This case opened the flood gates to negligence law suites. You can read the full case here.