[3] On December 18, Lawton and his men were en route to San Mateo along the Marikina River in a punitive expedition against Brig.

[4]: 160 [5] On December 19, the 11th captured Montalban, while Sargent's squadron made for San Mateo, approaching the Filipinos in rain and mist.

[1][4]: 161 Despite Lawton's death and heavy enemy fire, American troops faced additional challenges from the monsoon conditions, which made the nearby river nearly impassable.

Two of Sargent's men located a ford and swam across the swollen river under fire and found a canoe, enabling them to ferry their comrades across.

[9] Before his death, Lawton had written about the Filipinos in a formal correspondence, "Taking into account the disadvantages they have to fight against in terms of arms, equipment and military discipline, without artillery, short of ammunition, powder inferior, shells reloaded until they are defective, they are the bravest men I have ever seen ..."[1]