From 2011 to 2013, Texas experienced its worst drought in recorded history. This event provided a unique natural experiment to assess species‐specific responses to extreme drought and mortality of four co‐occurring woody species: Quercus fusiformis, Diospyros texana, Prosopis glandulosa, and Juniperus ashei. We examined hypothesized mechanisms that could promote these species' diverse mortality patterns using postdrought measurements on surviving trees coupled to retrospective process modelling. The species exhibited a wide range of gas exchange responses, hydraulic strategies, and mortality rates. Multiple proposed indices of mortality mechanisms were inconsistent with the observed mortality patterns across species, including measures of the degree of iso/anisohydry, photosynthesis, carbohydrate depletion, and hydraulic safety margins. Large losses of spring and summer whole‐tree conductance (driven by belowground losses of conductance) and shallower rooting depths were associated with species that exhibited greater mortality. Based on this retrospective analysis, we suggest that species more vulnerable to drought were more likely to have succumbed to hydraulic failure belowground. The 2011–2013 drought in Texas was possibly the most severe drought in that area in over 1,000 years. We found, counterintuitively, that species that had the most embolism‐resistant xylem had the greatest mortality. We also found that belowground hydraulic failure was the most likely cause of mortality. Several previously used metrics for predicting mortality were not consistent with mortality in our study. This work has strong implications for previous work that has used branch resistance to hydraulic dysfunction as a proxy for the drought tolerance of entire plants.