coolant tank leaking for sure/anything that might have caused this

/coolant tank is leaking on daughters Neon.The car has used oil for years,appx 1 qt very 300-450 miles.It does not leak any oil,but seems to burn oil.I set trip gauge and check every 300-500 miles.checked oil level last night,was again.Could something with engine have caused this to get so hot that cause tank to leak ? Like I said,overflow tank was empty,added water to this  only,mount rt frt against fire wall,yellow cap said coolant,appeared to be leaking  at bottom of tank as fast a I could put water in. or is it just tank got cracked and leaked.Do not have alot of money to put into,just put new tires on appx 3 weks ago.