It happened around 5:00 a.m. Sunday at the Wyndham Garden Hotel in Essington.
Officials say a guest broke the fire sprinkler inside a room, tripping the alarm.
The hotel evacuated their 600 guests.
Hotel staff had to work overtime to clean up the 50 rooms that sustained thousands of dollars in water damage.
Several teams from this weekend's Penn Relays were staying there.
No word yet on who was responsible but the hotel says they will not be pressing charges.