I am seeing Coolant level sign..what could be the problem ?

What is your question?

Yesterday t car engine exchust fan came bit closer to radiator.today I took the car to garage and the place the radiator in right place. and they said my radiator tank has very little water.SO they put water and that it seems working fine.Later on I start driving the car and drive almost for hour and the temrature indicates 120 which very near to Red mark.Then it stopped.I restart the car then somehow managed to come home.Now in the evening I keep the car so that it can cool down now it showing Coolant Level.Please advice.What could be the cause.What should I do.Here outside temprature is very High. Thanks in advance Juba,South Sudan