。
I accidentally spilled iced tea on my shirt.
Literal
Shirt [on-に] iced-tea [subject-が] got-on-[regret-てしまった].
かかる 'to be applied to / fall upon' is used for liquids or things that end up on a surface without the agent intending it — here, the iced tea 'got on' the shirt. The ~てしまった ending carries the regretful-completion nuance, framing the spill as an unfortunate unintended event. アイスティー is a katakana loanword, one of many English-origin beverage names. The subject of the spilling action isn't specified — English needs 'I accidentally spilled,' but Japanese lets the event happen to the shirt passively.