危在旦夕 on the verge of collapse
Explanation
危在旦夕是指情况非常危险，随时可能发生不好的事。旦夕是指早晨和晚上，比喻时间短，形容危险就在眼前，非常紧急。
Wei Zai Dan Xi means the situation is very dangerous, something bad can happen at any time. Dan Xi means morning and evening, which symbolizes the shortness of time, and describes that the danger is imminent, very urgent.
Origin Story
在古代的战场上，两军对峙，战火纷飞。一方的将军，名叫李将军，他骁勇善战，在战场上所向披靡。可是，这一仗，李将军却陷入了危机。敌军人数众多，而且个个都是身经百战的精兵强将，李将军的部队已经无力抵抗，危在旦夕。就在这时，李将军的副将，名叫赵将军，他冷静地分析了战场形势，发现敌军虽然人数众多，但他们的阵型却很松散。赵将军立即命令士兵们用弓箭向敌军发射密集的箭雨，打乱了敌军的阵型。敌军顿时乱作一团，李将军趁机率领部队发动反攻，最终取得了胜利。
On an ancient battlefield, two armies faced each other, with the flames of war blazing. One general, General Li, was a brave and capable warrior, invincible on the battlefield. But in this battle, General Li was in a critical situation. The enemy army was numerically superior, and all of them were experienced, battle-hardened soldiers. General Li's troops were unable to resist, and they were on the verge of defeat. At this moment, General Zhao, Li General's deputy, had his moment. He calmly analyzed the situation on the battlefield and noticed that while the enemy army was large, their formations were loose. General Zhao immediately ordered his soldiers to fire a dense barrage of arrows at the enemy army, disrupting their formations. The enemy army fell into disarray, General Li seized the opportunity and led his troops in a counterattack, ultimately achieving victory.
Usage
危在旦夕这个成语常用来形容十分危险，情况紧急，需要立刻采取措施。多用于警示，提醒人们注意危险。
The idiom Wei Zai Dan Xi is often used to describe a very dangerous situation, where urgent action is required. It is often used as a warning to alert people to danger.
Examples
-
这场比赛我们危在旦夕，一定要全力以赴。
zhe chang bisai women wei zai dan xi, yi ding yao quan li yi fu.
We are in a critical situation in this game, we must go all out.
-
这个项目已经危在旦夕，我们需要尽快找到解决办法。
zhe ge xiang mu yi jing wei zai dan xi, women xu yao jin kuai zhao dao jie jue ban fa.
This project is on the verge of collapse, we need to find a solution as soon as possible.
-
他的病情危在旦夕，医生正在全力抢救。
ta de bing qing wei zai dan xi, yi sheng zheng zai quan li qiang jiu.
His condition is critical, doctors are doing everything they can to save him.