At least four deaths have been blamed on Tropical Imelda, which deluged parts of Texas and Louisiana this week. Boat rescues were still being carried out on late Friday, when 60 residents in Houston had to be evacuated after flood waters trapped them in their homes. Imelda is the wettest tropical cyclone in U.S. history, according to the Associated Press. At least 16 feet of standing water has been reported in some areas where waters are not expected to recede until later in the weekend. Three of the known deaths were from drowning, and one was caused by electrocution after a man tried to move his horse to safety. Authorities to not rule out the death toll rising. “The issue is that you can’t get 40 inches of rain in a 72-hour period and be fully prepared for that,” Jefferson County spokeswoman Allison Getz told The AP on Friday. “At this point we haven’t been able to fully assess what’s happened.”