HOUSTON, Texas (KTRK) -- Police are looking for the group of masked thieves they say tried to steal an ATM from a Houston Methodist hospital in northwest Harris County.Officials tell Eyewitness News five to eight people broke in through a window in the cafeteria of the Willowbrook location.They grabbed the ATM and began carrying it out of the building, until a security guard making his rounds saw them.The thieves dropped the ATM and took off in two vehicles.Police are checking surveillance video to see if cameras caught a better look at the thieves or the vehicles.